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It is doubling membrane. The grana are absent. Developing thyllakoids are present in the stroma. In presence of light th
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CELL BIOLOGY

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CELL

The cell is defines as living unit of life or basic unit of life or structural and functional unit of life or fundamental unit of life or autonomous and self contained unit of the life. In 1665, Robert Hook discovered cell. In his experiment, he cut the cork pieces. Then he observed under his microscope and found many small compartments in it. He named each compartment Cell. In 1838, German Botanist Schleiden occluded that the plant body is also composed of cells. In addition, in 1839 German Zoologist Theodor concluded that the animal body is also composed of cells. Why cell is considered as basic unit of life or why cell is called self contained or autonomous unit? The cell is smallest unit of life. A single cell can perform different life processes as it can digest food, respire, excrete, reproduce, and grow. The cell carries different metabolic activities. The body function is out come of the different activities of the cell. So the cell is considered as basic unit or self contained or autonomous unit of life. Cell Theory  Schleiden in 1838 and Schwann proposed cell theory in 1839. It states that  Cell is a mass of protoplasm containing nucleolus and is bounded by a membrane.  All the cells are similar in chemical composition and metabolic activities.  Living things are composed of cells  The function of organisms is the outcomes of cell activities and interaction of cell components. Objection of cell theory  Bacteria and cyan bacteria do no contain nucleus  Some fungi contain many nuclei in branched body  There is no cellular organization in virus Sanjaychauwal.wordpress.com



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To include all the living organisms the cell theory proposed by Scleidan and Schwann can be modified which is called cell principle  Cell is a mass of protoplasm containing nucleus or in lack of nucleus nuclear materials is taken  Living things are made up of cells  Cell can store genetic information and express from generation to generation  Cell sometimes assume forms, which no longer have all the characteristics of the cell. What is cellular totipotency Even a single cell of a plant body has a power to regenerate entire plant body. This is called cellular totipotency. In 1950, Steward conducted an experiment on carrot. In this experiment, He removed small piece of carrot phloem, kept the piece in liquid medium. Phloem cells divided producing cell clusters. The clusters are kept on solid medium, after few days a plant grew in it. Difference between unicellular and multicellular organisms In unicellular organisms the body is single cell, single cell perform all the life activities, Cells are larger in size, easily infected and susceptible for damage, Amoeba, Paramecium In multicellular organisms, number of different types of cells forms body, the body function is outcome of the cellular activities of different cells, cells are usually smaller is size, not easily susceptible to damage, higher plants and animals

Types of cells Prokaryotic cell Sanjaychauwal.wordpress.com

Eukaryotic cell ②

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Small in size (range from 10010000nm) Usually gelatinous sheath is present Cell wall is made up of amino sugar and muramic acid. Mesosome is present, the power house of the cell Nuclear membrane and nucleolus is absent DNA is found freely in cytoplasm Histone protein is absent in DNA, So called naked DNA Cell organelles are absent Flagella is simple. Pili are present Ribosomes are small and 70 S type. Plasmid may be present Cyclosis is absent Cell division is amitosis. Cell cycle is short Spindle fibers are absent Bacteria and Cyanobacteria

Larger in size (range from 10000100000nm) Usually gelatinous sheath absent In animal cell, cell wall is absent but in plant cell it is made up of cellulose Mesosome is absent. Mitochondria are power house of the cell Nuclear membrane and nucleolus are present DNA is bounded by nuclear membrane. Histone protein is present in DNA so called closed DNA Cell organelles are present Flagella are compound (9+2 pattern) Pili absent Ribosomes are large and 80S type Plasmid is absent Cyclosis is present Cell division is mitosis and meiosis Cell cycle is long Spindle fibers are present Higher plants and animal cell There are two types of cells found in organisms. The differences are as follows. STRUCTURE OF EUKARYOTIC CELL Shape The shape is variable like round oval irregular spherical elongated or tubular etc Size The size is also different in unicellular organisms it range from 1µm to 1 mm. in multicellular organisms it range from 1- 100µm Cell Components Sanjaychauwal.wordpress.com



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Cell wall It is outermost layer of plant cell. It is a rigid and protective layer. It is composed of different layer Middle lamella: It is present between the walls of adjacent cells. It acts as cementing materials between two cells. It is made up of carbohydrate, Ca and Mg Primary cell wall: It is found on either side of middle lamella. It is made up of middle lamella. It is made up of cellulose, hemi cellulose. It is thin elastic and permeable. Secondary cell wall: it is found on inner side of primary cell wall. It is thick non-elastic and rigid it is made up of cellulose lignin and pectin Function of cell wall It provides rigidity to the cell. It protects the inner mass of the cell. Maintain the shape of the cell. Balance the osmotic pressure. It helps in absorption of water. Cell membrane The most important structure of the cell is its membrane, for it is the cell membrane that controls and regulates what enters and leaves the cell. The cell membrane is made of two layers of lipids, called a lipid bilayer. The lipid bilayer is made of lipids (fats) and phosphates, normally called phospholipids Phospholipids have a polar end, and a non-polar end. In making membranes, the non-polar ends of both layers face each other, while the polar end faces the outside and inside of the cell. There are two theories for model of cell membrane Sandwich Model In this, there are two layers of protein outer and inner. In between two protein layers, there are two phospholipids layers. The heads of the phospholipids molecules face towards protein layer and the tails toward the centre. Fluid Mosaic Model In this model, there are 3 layers, two layers of protein and one layer of phospholipids. The phospholipids are liquid in nature. Therefore, molecules can exchange their position. This is called transition movement. The molecules can Sanjaychauwal.wordpress.com



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also interchange between two layers this is called flip-flop movement. The Proteins are of two types Peripheral protein (extrinsic protein): They are present either inner or outer surface. Intrinsic protein: It is partially or completely embedded in phospholipids. Function of cell membrane It is the outer covering membrane of animal cell, which maintain cell shape, helps in diffusion, helps in osmosis endocytosis (intake of large molecules in to the cell) and exocytosis Expelling of large molecules of liquid or solid from the cell. Protoplasm It is found inside cell membrane. It is a liquid mass viscous in nature. It contains several living and non-living things. It is divided into two parts Cytoplasm: It is liquid mass present between plasma membrane and nuclear membrane. it is differentiated into two layers The outer ectoplasm which is non granular and inner endoplasm which is granular containing cell inclusions and cell organelles. Nucleolasm: It is liquid material within nuclear membrane. Cell Organelles They are living sub cellular structures which are embedded within cytoplasm. a) Mitochondria (Mitochondrion) Its shape is variable and the size range from 2-6 micrometer. It is double membrane structure. Its outer membrane is smooth and regular. Its inner membrane gives finger like projections towards inner side called cristae. The surface of the cristae contains number of stalked and globular proteins called oxysomes. The cavity bounded by membrane is filled with a liquid mass called matrix. The matrix contains DNA RNA, inorganic and organic molecules. The mitochondria have its own DNA so it expresses its nature and characters own self. It is distributed in the cytoplasm. Function of mitochondria It stores various types of enzymes used in aerobic respiration. It releases energy during oxidation of food material in aerobic respiration and stores energy in the Sanjaychauwal.wordpress.com



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form of ATPs so it is considered as the powerhouse of the cell. It can synthesize some proteins and it is carrier of genetic material. b) Plastids Plastids are photosynthetic pigments containing bodies found in the cytoplasm of plant cell. There are three types of plastids Chloroplasts Plastids, which contain green colored photosynthetic pigments, are called chloroplast. It is double membraned. A kind of fluid is enclosed by membrane is called stroma. In the stroma number of sac like membranes found called thyllakoid or lamellae. The group of thyllakoid is called granum. The thyllakoid that connects one granum to another granum is called fret. The stroma also caontains DNA RNA and other organic and inorganic substances. Function of chloroplast The main function of chloroplast is photosynthesis. The green colored pigments, the chlorophylls traps solar energy and the energy is then converted into chemical energy C6H12O6 with the combination of CO2 and H2O. It is also carrier of genetic materials, as it possesses its own DNA. Chromoplast The plastid, which contains colored photosynthetic pigment other than green, is called chromoplast. Yellow coloured pigments are called Xanthophylls. Orange colored pigments is called Carotenes Red colored pigments are called Erythrocyanine and blue colored pigments are called Phycocyanine. The chromoplasts are also doubling membrane. In the stroma grana are absent and the thyllakoids are found degenerating. They are present in colored parts of the plant body. Their main function is to make colorful the body parts like colorful parts of the flower attracts insects. Leucoplast The plastids which contain colorless pigments are called leucoplast. It is doubling membrane. The grana are absent. Developing thyllakoids are present in the stroma. In presence of light the leucoplast changes into chloroplast. Sanjaychauwal.wordpress.com



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The main function of the leucoplast is to store food materials. It is present in the stem and root. The leucoplast which store starch is called amyloplast, which stores oil, is called elaioplast and which stores protein called aleuroplast. c) Endoplasmic Reticulum It is the network of tube like structures and sac like structures. It arises from nuclear membrane and extends up to cell membrane. The endoplasmic reticulum is formed by three structures. Cisternae: They are long elongated flattened unbranched sac like structures lie parallel to each other. Vesicles: They are minute spherical or oval sac like structures Tubules: They are branched tube like structures they form net work with cisternae and vesicles. Function of ER It provides mechanical support to the cell. Therefore, it is also known as cytoskeleton. It synthesizes proteins and hormones. It helps to transport ions, molecules and impulse or metabolites. It forms nuclear membrane. It also forms new cell membrane and components. There are two types of ER Rough ER It bears ribosomes on its surface It is found near nuclear membrane It is formed by nuclear membrane In it mainly cisternae are found

Smooth ER It bears no ribosomes It is found near cell membrane It is formed by rough ER In it mainly tubules are found d)

Golgi body It is also known as lipochondria or dictyosome It arises from ER and is formed by four structures. It lies near cell membrane Cisternae: They are curved with dilated ends and are parallel to each other Vesicles: They lie on convex side of cisternae Vacuoles:They are larger sac like structures lie on concave side of cisternae. Sanjaychauwal.wordpress.com



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Tubules:

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They formed net with cisternae vesicles and vacuoles

Functions of Golgi body It forms new cell membrane, It forms cell wall components, It secrets hormones, It stores proteins and fats. It forms vesicles and lysosomes e) Ribosome They are small dense granular particles of RNA and proteins. It is also known as ribonucleioproteins. They are found freely in cytoplasm and found on the surface of endoplasmic reticulum and within some cell organelles. It is not bounded by any membrane. Each particle of ribosome consists of two subunits i.e. One larger and another smaller cap like subunit over larger subunit. There are two types of ribosome 70S type It is smaller in size and the number of protein is 55 The ratio of RNA and protein is 2:1 Molecular weight is 2.7×106 Dalton When it break down then it gives 50S and 30S subunits It is found in prokaryotic cells (1 dalton = 1.6*10-24)

80 S type It is larger in size the no of proteins is 82 The ratio of RNA and protein is 1:1 Molecular weight is 4.5*106 when it breaks down it gives 60S and 40S subunits it is found in eukaryotic cells

Function of Ribosome It is the site of protein synthesis, it also stores protein, and therefore ribosome is called protein Factory. f) Lysosomes The lysosomes are vesicles like structures bounded by single membrane; the lysosome contains several enzymes that digest extra cellular and intra cellular substances. Lysosomes digest cell organelles causing death of cell. Therefore, it is called suicidal bag. There are four types of lysosomes Primary lysosomes: Sanjaychauwal.wordpress.com



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The newly formed lysosomes containing inactive enzymes are called primary lysosomes. Secondary lysosomes These are formed by fusion of primary lysosomes with active enzymes, which digest unnecessary particles. Tertiary lysosomes: Lysosome containing undigested food is called tertiary lysosome or residual body. Autolysosome: Lysosome which digests cell organelles is called auto lysosome. Function of Lysosome It digests dead cells, it digests extra and intra cellular particles, it ingest particles g) Centrosome The centrosome is globose body, which consists of two star shaped structures called centrioles. Each centriole consists of nine rows of triplet fibrils and remains surrounded by cytoplasmic area called centrosphere. When centrosome is present at the base of flagella or cilia then it is called basal body. Function of Centro some During cell division, it produces spindle fibers; the basal bodies control the movement of cilia and flagella. h) Micro bodies They are small vacuole like structures, which are of following types. Sphaerosomes They are small lysosomes like structures. They contain enzymes like lysosomes, which digest lipid and other substance. They may also act as lysosomes usually present in plant cells. Glyoxisomes They are sphaerosomes like structures, which contain rod like enzymes, which digest lipid and decompose aminoacids. Peroxisomes These are microbodies, which contains two types of enzymes. The enzyme Catalases catalyses the decomposition of Hydrogen Peroxide to Water and Oxygen and The enzyme Oxidases oxidize organic compounds. Sanjaychauwal.wordpress.com



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i) Microtubules Microtubules are long cylindrical hollow tube found in cytoplasm. They are made up of tubulin protein. Each triplet fibrils of centriole is made up of one microtubules. It provides mechanical support to cell and helps in cell division. j) Microfilament They are long cylindrical solid tubes found in cytoplasm. The function is helps in cyclosis, locomotion, and cell division k) Vacuoles They are single membraed sac like structures, which is filled with liquid mass called vacuolar sap (cell sap). Its membrane is called tonoplast. Function of the vacuole It stores various organic and inorganic molecules, it balances the water in cell, it also helps in growth and elongation of cells, cell sap exerts turgor pressure, which keeps the plant cell turgid. l) Cilia and Flagella They are hair like structures. They rise from basal bodies; they are made up of 11 filaments and fibrils. In 11 fibrils, nine fibrils are arranged in outer ring and two fibrils remains at centre. Outer filament consists of two microtubules a and b. Microtubules are connected by radial spoke with central fibrils.

Difference between Cilia and Flagella Cilia It is shorter and smaller in size Covers entire cell surface

Flagella It is longer and larger in size Usually one or two flagella are found at one end of cell Cilia shows sweeping movement Flagella show undulating movement. Helps in locomotion and to Flagella helps in locomotion capture food Sanjaychauwal.wordpress.com



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m) Nucleus It is the important cell organelles, which controls all the activities of the cell. It also carries the hereditary information of the cell. Its structure is spherical or oval. It is present one or more in number in a cell. he nucleus is doubling membraned. The outer membrane is rough and inner membrane is smooth. The nuclear membrane is porous and selective permeable. The pores help in exchange of substance between cytoplasm and nucleoplasm. The nucleoplasm is semi liquids bounded by nuclear membrane within nucleoplasm DNA RNA enzymes are found. In nucleoplasm there is round structure of ribonucleoprotein, which is called nucleolus. Nucleolus forms ribosomes. In nucleoplasm there is net like structures of fine thread, which is called chromatin network or simply called as chromatin. During cell division, this network gives fine separate thread like structures called chromosome. There are two types of chromatin Heterochromatin Euchromatin  Densely packed region of  Loosely packed region of chromatin chromatin  It remains loosely coiled and  It remains tightly coiled and diffused during interphase they are condensed during  Loosely stained interphase  It possesses large amount of DNA  Deeply stained and less amount of RNA  It possesses large amount of  Euchromatin is genetically active. RNA and less amount of DNA  Due to small amount of DNA present they are genetically inactive Cell inclusions Non-living substances embedded in cytoplasm are called cell inclusions. Such as proteins amino compounds, oil, cellulose, sugar etc are inclusions ergastic bodies. Cell inclusions are divided into three categories they are Reserved materials The metabolic products stored inn plant cell forms the reserved materials. They are either nitrogenous compounds like proteins, amino acids or non nitrogenous compounds like starch cellulose, insulin, fats, oils, glycogen etc. Sanjaychauwal.wordpress.com

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Secretory materials Certain substances formed during plant metabolism but not concerned with nutrition. Such materials are called secretory materials. They are of following types Plant pigments: the color producing substances of plants are plant pigments Enzymes or Hormones: These are nitrogenous secretory products and are soluble in water Nectar: It is secreted by nectar secreting glands known as nectarines, which helps to attract the insect for pollination. Excretory materials These are the by products of plant metabolisms and are of no use to the plants such as resins, gums, oils, organic acid, alkaloids, latex, tannins, inorganic compounds like urea caco3 and silica. Energy flow Cell utilizes energy either in the form of light or in the form of chemical (food). The cells of green plants absorb light energy and synthesize food but cells of animals absorb chemicals from the surrounding. The food absorbed by cells gets oxidized to release energy and energy is released and stored in eh form of ATP. Flow of information The flow of information through a cell takes tow routes Intrinsic Information The DNA forms RNA, the process is called transcription. The RNA forms proteins, the process is called translation. Then these proteins regulate al the cell activities. DNA………………………RNA…………………………………..Proteins. Extrinsic information Certain glands cell secretes hormones. These hormones can regulate al the cell activities. The hormones can be transmitted from one cell to other cell. For example insulin is produced in pancreas but control the activities of blood cell. Cell Division

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It is a cyclic process in which the division of nucleus is followed by division of cytoplasm as a result daughter cells are formed. Cell Cycle All the changes that take place during cell growth and cell division are called cell cycle. Cell cycle can be divided into following phases Interphase: The stage when cell becomes ready to divide is called interphase. It is subdivided into G1 Phase, G2 Phase, S Phase Karyokinesis: It is the process of division of nucleus. It is subdivided into Prophase, Metaphase, Anaphase, Telophase. Cytokinesis It is the process of division of cytoplasm. TYPES OF CELL DIVISION 1. Amitosis cell division or direct cell division This cell division takes place in prokaryotic and unicellular eukaryotic animals. During the process, the nucleus becomes elongated. The nucleus divides into two nuclei by forming constrictions. The cytoplasm also divides into two parts and the cell membrane is also constricted. Thus two daughter cells are formed. 2. Mitosis cell division The process of cell division in which al the chromosomes replicate and separate into two groups having equal number of chromosomes as their parent cell. Thus two nuclei are formed. During the process Interphase The nucleus is metabolically active. This phase is divided into 3 sub phases G1 phase: Protein and RNA synthesis occurs, nucleus appears to contain fine delicate threads, and chromosomes are fully extended. S phase: DNA and protein synthesis occurs, chromosomes replicate, synthesis of RNA stops. G2phase: Synthesis of DNA stops, Enzymes are formed, cell organelles multiply. Karyokinesis Prophase Sanjaychauwal.wordpress.com

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 Chromosomes become slender elongated distinct and separate threads  Chromatids lie parallel to each other and are connected by Centro mere  Chromosomes become shorter and thicker and Matrix sheath appears around chromatids.  Nuclear membrane and nucleolus start to disappear  Centrioles appear and start to move towards pole. Metaphase  Spindle fibres appear and centromere also produced fine fibers called tractile fibers.  Spindle fibers connect centromere of each chromosome  All the chromosomes arrange at the equatorial plane of the cell.  The centromere of each chromosome divides into two centromeres in longitudinal way  One centromere of each chromosome is connected with spindle fiber of one pole and another Centro mere is connected with spindle fiber of another pole. Anaphase

 A kind of repulsive force is developed between two centromeres of each chromosome  One of the two centromeres having its own chromatids moves towards one pole and another cnetromere move towards another pole.  Two groups of chromosomes are formed at each pole due to contraction of spindle fibers

Telophase  Spindle fibers disappear  Chromosomes at each pole become elongated long coiled Sanjaychauwal.wordpress.com

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forming chromatin network  Nuclear membrane and nucleolus reappears  Thus, two nuclei are formed at each pole.

Cytokinesis The process of division of cytoplasm is called cytokinesis a. Cell plate Method  Number of vacuoles and vesicles fused together at the middle of cell between two nuclei forming a plate like structures. The plate like structures are called phragmoplast  Cell wall components accumulates at the each side of the cell plate  And single cell is divided into two daughter cells  This method takes place in plant cell. b. Cleavage Method  No cell plate is formed in this method.  The cytoplasm is constricted directly from the constriction of cell membrane and ultimately the cell is divided into two parts.  This method takes place in animal cell. Significance of Mitosis  It keeps the chromosome number constant and genetic stability in daughter cells, so the linear heredity of an organism is maintained.  It helps in growth and development of zygote into adult.  It plays a significant role in wound healing, replacement of old and decaying and dead cells and regeneration of lost parts.  It helps the cell in maintaining proper size  It also helps in asexual reproduction by fragmentation, budding, stem cutting etc.  Through the process, equilibrium is maintained in the amount of DNA and RNA 3. Meiosis Cell Division Sanjaychauwal.wordpress.com

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The process of cell division which takes place in a diploid cell and produces four haploid cell is meiosis cell division i.e. Each cell having half the number of chromosomes as that of parent cell. Meiosis I The meiosis I the division is called reductional division or heterotypic division because the cell divides into two daughter cells having chromosome number half in two daughter cells as that present in the mother cell. Karyokiesis Prophase I It is very complex and ling phase. It is further divided into five successive sub phases Leptotene  The nucleus increases in size  Chromosomes become slender and separate and distinct threads  Chromosomes contain bead like structures called chromomeres. Zygotene  The homologous chromosomes make pair  The process of making pair by homologous chromosomes is called synapses.  Each pair is called bivalent  The process of synapses is initiated by a kind of attraction force between homologous chromosomes.  The homologous chromosomes can be defined as morphologically and genetically similar one paternal and one maternal chromosome are called homologous chromosomes. Pachytene  The homologous pair coiled around each other, Chromosomes replicate,  Chromosomes become shorter and thicker  Each bivalent appears four stranded Sanjaychauwal.wordpress.com

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Diplotene  Uncoiling of chromosomes takes place from centromere due to a kind of repulsive force  Some parts however remain still attached at certain points  The attaching points are called chaismata.  At chiasmata chromosomal segments are broken and rejoined cross wise i.e. Exchange of maternal and paternal chromosomal segments.  This phenomenon is called crossing over  Some auther mention the crossing over takes place in pachytene stage. Diakinesis  Chiasmata move towards the end of chromosome. This process is called terminalization  The nuclear membrane starts to disappear  Nucleolus also disappear Metaphase I  Spindle fibers appears  Chromosomes arrange at the equator centromere of each bivalent face towards opposite pole.  One centromere of each bivalent becomes attached with spindle fibers of one pole and another centromere of each bivalent gets attached with spindle fibers of another pole. Anaphase I  Each bivalent separate together  Separated bivalent move towards opposite poles due to contraction of spindle fiber  Two groups of chromosomes are formed at each pole having haploid number of chromosomes

Telophase I Sanjaychauwal.wordpress.com

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   

Chromosomes arrange into two groups one at each pole Nuclear membrane and nucleolus reappears Spindle fibers disappear Chromosomes become long elongated to form chromatin Cytokinesis: It may or may not occurs

Meiosis II It is called equational division or homotypical division because the cells produced after meiosis I undergo further division to produce four cells where chromosome number remains same as that of parent cells, similar to mitosis. Karyokinesis Prophase II The Chromosome become shorter and thicker, Nuclear membrane and nucleolus disappear. Spindle fibers start to appear

Metaphase II  Chromosomes arranged at the equator  The centromere of each chromosome divides into two centromeres in longitudinal way.  One centromere of each chromosome is connected with spindle fiber of one pole and another centromere is connected with spindle fiber of another pole.

Anaphase II  A kind of repulsive force is developed between two daughter centromeres  One of the two centromeres having its own chromatids move towards one pole and another centromere move towards another pole Sanjaychauwal.wordpress.com

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 Two groups of chromosomes are formed at each pole due to contraction of spindle fibers.

Telophase II  Chromosomes organize into nucleus at each pole  Chromosomes become long, elongated forming chromatin  Nuclear membrane and nucleolus reappears  Spindle fibers disappears Cytokinesis Successive method The first cytokinesis takes place after meiosis first to form two daughter cells and second cytokinesis takes place after meiosis II to form four daughter cells. The process is called successive Method. Simultaneous Method In this method, cytokinesis takes place only after Meiosis II to produce four daughter cells.

Significance of Meiosis cell division  Gametes and spores are formed by meiosis divisions that are essential for sexual reproduction  Meiosis helps to maintain fix number of chromosomes in organisms  Crossing over causes the genetic variation among the species  It helps in alternation of generations of haploid and diploid generations of plants and animals  The segregation of paired chromosome resulting in different combination of character daughter cells. Differences between mitosis and meiosis Mitosis Sanjaychauwal.wordpress.com

Meiosis 19

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It occurs in somatic cells Mitosis division completed only in one division Prophase It is very short Synapses is absent No coiling and no replication takes place

It occurs in reproductive cells Meiosis division is completed in two successive divisions Prophase Prophase is very long Subdivided into 5 sub phases In Zygotene synapses occurs In Pahcytene homologous chromosome undergo coiling and replication occurs No chiasmata formation takes place In diplotene chiasmata formation and No crossing over takes place crossing over takes place No Variation occurs Variation occurs Metaphase Metaphase One metaphasic plate is formed Two metaphase plate is formed Contromere divides longitudinally Centromere does not divide in Meiosis I Anaphase but in II Two chromatids of each chromosome Anaphase separate and move towards opposite Homologous chromosomes separate and pole move towards opposite pole Each chromosome is single stranded Each chromosome is double stranded n meiosis I Telophase Telophase Nucleus id diploid Nuclei are haploid Two nuclei are formed Four nuclei are formed after Telophase II Two cells are produced after Four cells are produced after cytokinesis cytokinesis II

TAXONOMY The taxonomy is the branch of biology, which deals with identification, naming, and classification of organisms. The father of taxonomy is considered as Carolus Linnaeus. Sanjaychauwal.wordpress.com

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Binomial Nomenclature The system of giving scientific name to organisms by using two Latin words is called binomial nomenclature. For example Rana tigrina (Frog). The first word represents genus and the name is called generic name. The second word represents species and called specific name. Some of the scientific names of organisms are given below. Man Homo sapiens Lion Panthera tigris Onion Allium sepa Garlic Allium sativum Potato Solanum tuberosum Rat Rattus rattus Rules of binomial nomenclature  Scientific name should be in two Latin words.  The scientific name should be italicized.  Scientific name should be underlined in hand written script  The generic name should be started from capital letter and the specific name should be started from small letter.  The scientific name of the two or more organisms should not be similar. Two Kingdom System of Classification Carolus Linnaeus divided the organisms into two kingdoms, the plant Kingdom and the Animal Kingdom. This system was based on the characteristics of animals and the plants. Plant Kingdom Animal Kingdom The organisms of this kingdom The organisms of this kingdom are are autotrophic i.e. they bear heterotrophic i.e. they do not bear chlorophyll molecule chlorophyll They have cellulosic cell wall They don't have cellulosic cell wall around the cell in the cell The body is fixed at one place They show locomotion, not fixed They are less sensitive due to organisms absence of nervous system They are highly sensitive due to Their reserved food material is presence of nervous system starch Their reserved food material is Centrosome is absent in the cell glycogen Large vacuoles are present in the The centrosome is present in the cell cells Vacuoles are very small or absent Sanjaychauwal.wordpress.com

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The body is compact having definite The body is branched having shape definite shape

Shortcomings of Two Kingdom System of Classification The cell of bacteria consists of cell wall and it is heterotrophic. They show characters of both plants and animals. The body of fungi is highly branched and cell has cell wall but they are heterotrophic and the stored food is glycogen. Hence, they show both plant and animal like characters. A kind of protozoan named Euglena contains chlorophylls and shows locomotion. It also shows both plant and animal like characters. Five Kingdom System of Classification To include all the organisms, Robort H Whittaker in 1969 proposed a new system of classification. In his system, the organisms are included in five kingdoms. They are Monera, Protista, Fungi, Animalia, and Plantae. This system is based on cellular complexity, body structure, and mode of nutrition. General Characters Kingdom Monera This kingdom includes all the unicellular, microscopic, and prokaryotic organisms, which do not contain a well-defined nucleus, the nuclear material is freely found in cytoplasm, they lack well-developed cell organelles, they may be auto or heterotrophic Example: Bacteria and Cyanobacteria Sanjaychauwal.wordpress.com

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Kingdom Protista This kingdom includes all the unicellular but eukaryotic organisms which are: auto or heterotrophic, the cell contain well defined nucleus and cell organelles, all the vital activities are performed by single cell, Example: Euglena, Volvox, Paramecium, Amoeba Kingdom Fungi This kingdom includes all the multicellular few are unicellular eukaryotic organisms, which are: Heterotrophic that grows on decaying organic matter, achlorophyllous, branched body, do not show locomotion, cell wall is made up of chitin, reserve food is glycogen. Example: Yeast, Mucor, Mushroom. Kingdom Animalia This kingdom includes all the multicellular eukaryotic organisms, which are: heterotrophic that feeds on autotrophic organisms through different way, show movement, no cell wall is present, reserve food is glycogen, body is compact. Example: Rat, Pigeon, Frog Kingdom Plantae This kingdom includes all the multicellular eukaryotic organisms which are: autotrophic due to having chlorophyll molecules for photosynthesis, cellulosic cell wall is present, reserve food is starch, do not show locomotion, body is branced. Example: mustard, mango etc. In this system the monera are thought to have originated at first. The protista are originated from monera. From protista Fungi and animalia and plantae were evolved. This shows a evolutionary relationship among five kingdoms. This relationship is called phyllogenetic relationship. The evolutionary history of an organism is called phylogeny. The classification based on the phyllogenetic relationship is called phylogenetic system of classification. Taxonomic categories Plant Animal Sanjaychauwal.wordpress.com

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Kingdom Division Class Series Order Family Genus Species

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Kingdom Phylum Class Series Order Family Genus Speceis

There are different categories or groups to classify or to include related organisms in same group to make easier for study are called taxonomic categories. Any category of the taxonomic group of any rank is called taxon (pleural-taxa)

Taxonomic Higherarchy The arrangement of taxonomic categories based on the taxonomic rank is called taxonomic higherarchy. The highest rank of the taxonomic categories is kingdom and the lowest rank is species. What is species or why species is called basic unit of taxonomy? The species means group of individuals having very close relationship and they can reproduce successfully. Below species, there is no any rank of taxonomic category. Therefore, it is called basic unit of taxonomy, for eg. tigrina is the species of frog. Genus: The group of two or more species having similarity in many characters is called genus, for eg. Rana is the genus of frog. Family: The group of two or more genus having similarity in many characters is called family, for eg Ranidae is the family of frog. Order: The group of two or more family having similarity in many characters is called order, for eg Anura is the family of frog. Division: The group of two or more orders having similarity in many characters is called division, for eg Gnathostomata is the family of frog. Class: The group of two or more divisions having similarity in many characters is called class, for eg Amphibia is the family of frog. Sanjaychauwal.wordpress.com

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Phylum: The group of two or more classes having similarity in many characters is called Phylum, for eg Chordata is the family of frog. Kingdom: The group of two or more phyla having similarity in many characters is called kingdom, for eg Animalia is the family of frog. KINGDOM MONERA BACTERIA Bacteria are discovered by Anton Van Leeuwenhoek in 1676. They are found everywhere in air, water, soil, and bodies of organisms. There is no natural death of bacteria. They are killed either using chemicals or by infecting with virus. Morphology Size of the bacteria varies from 2-5µm and 0.3-0.8µm width in rod shaped bacteria. In spherical bacteria the size varies from 0.5 – 1µm in diameter. Spherical bacteria: the bacteria having spherical in shape are called coccus bacteria. The coccus bacteria may be found singly and freely are called monococcus or micrococcus. When they are found in the group of two is called diploccus. Sometimes they are found in the group of four are called tetracoccus. Some of them are found in chain are called streptococcus and some are found in large group like bunch of grape called staphylococcus. Rod like Bacteria: the bacteria having shape of the cell is if rod like called bacillus. The bacillus bacteria are found in singly and freely are called monobacillus. Some of them are found in the group of two are called diplobacillus. They are also found in chain are called streptobacillus. Helical Bacteria: The bacteria having shape of the cell is coiled called helical bacteria. These are of two types: Vibrio: The bacteria having the shape are comma like are called Vibrio. eg. Vibrio cholera. Spirillum: The bacteria having shape is helically coiled are called Spirillum. Cell Structure Sanjaychauwal.wordpress.com

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Capsule The capsule is the outer most covering of gelatinous substance is called capsule. It is made up of polysaccharides. The capsule may be absent in some bacteria. They are called noncapsulated bacteria and other having capsule are called capsulated bacteria. Usually the capsulated bacteria are poisonous or virulent that causes diseases and the non-capsulated bacteria are non-virulent. The function of the capsule is to protect cell, protects from desiccation and secrets poisons. Cell wall It is found under the capsule in capsulated bacteria and the outermost layer in noncapsulated bacteria. It is rigid and is composed of a kind of complex substance called peptidoglycan or Murine or Mucopeptide. The peptidoglycan is composed of complex carbohydrates called N-acetyle muramic acid and N acetyl glucosamine and aminoacid ie. L alanine, D alsnine and D glutanic acid. Polysaccharides and lipids are also present in cell wall. On the basis of cell wall structure types Gram positive In gram positive bacteria cell wall is thick (25-30nm) The peptidoglycan amount is 2080% There is no lipopolysacharide in cell wall Lipid is about 0-2% They retain violet or blue colour in Gram's stain Sanjaychauwal.wordpress.com

and stain retaining property bacteria are two Gram Negative Bacteria The cell wall is thin about 10-15nm Peptidoglycan is 10-20% Lipopolysaccharide layer is present Lipid is about 10-20% They retain pink or red color in Gram's stain

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Function of cell wall It provides rigidity to the cell, it maintains cell shape; it protects protoplasm of the cell. Cell membrane It is thin elastic and permeable membrane made up of protein and phospholipids. The main function is protection, maintains cell shape, and helps in osmosis and diffusion. Reproduction Bacteria usually reproduce by asexual method. Binary fission The nuclear material becomes enlarged and divides into two parts. Constriction is made in the middle of the cell on the cell membrane dividing cytoplasm into two parts. Ultimately, a cell is divided into two daughter cells. This method is very common and simplest method of reproduction in bacteria. By this method, about 2500,000 bacterial cells are produced in an hour. Budding During the process, small bud is developed on outer side of bacteria cell with cytoplasm. The bud gets enlarged and separated from mother cell. Gonidia In cell nuclear material and cytoplasm divides and arranged forming a tiny bodies. Each body having cell wall, cytoplasm and genetic material is called gonidium, which releases out and germinate to produce new bacterial cell. Endospore Under unfavorable condition a round spore is formed in the bacterial cell which is thick walled and highly resistant. The spore is oval or spherical called endospore. During endospore formation, the genetic material gets divided into two parts. One part migrates at one end of the bacterial cell. The cytoplasm is constricted at that end by constriction of cell membrane. A spore is then formed at that end. It Sanjaychauwal.wordpress.com

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releases out in the soil and may remain viable for several years. Under favorable condition, it germinates to produce new bacterial cells. Sexual reproduction The recombination of genes of bacterial cells through different ways from one to another cell is considered as the sexual reproduction. This is of following types Transformation The process of entrance of exogenous DNA from one bacterial cell to another cell is called transformation. The cell which gives exogenous DNA is called donor ant the cell which take is called recipient. Transduction The process in which genetic material from one bacterial cell transfers to another bacterial cell by means of viruses is called transduction. The virus evolve in this process is called bacteriophage. Conjugation The process in which two bacterial cells conjugate with the help of pili is called conjugation. During the process one bacterial cell transfer the chromosomal segments to another bacterial cell. Economic Importance Beneficial Activities In Agriculture, the bacteria are mostly important for following reasons 1. Nitrogen fixation Plants cannot trap nitrogen from the atmosphere but bacteria can fix nitrogen and change it into nitrogenous compounds. The phenomenon is called nitrogen fixation. The bacteria, which fix atmospheric nitrogen, are called nitrogenfixing bacteria. Some of the nitrogen fixing bacteria are found freely in soil are called free-living bacteria, eg. Clostridium and Azotobacter. Some of them are found in root nodules making association with leguminous plants called symbiotic bacteria, eg. Rhizobium. 2. Nitrification Some bacteria convert ammonium compounds into nitrates in the soil. The process is called nitrification. The bacteria that take part in this process are called nitrifying bacteria, eg. Nitrobacter and Nitrosomonas. Nitrosomonas Nitrobacter Sanjaychauwal.wordpress.com

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Ammonia………………Nitrites…………………….Nitrates 3. Ammonification Some bacteria utilize proteins of dead bodies and convert it into amino acids. These amino acids are converted into ammonia by some bacteria. The process is called ammonification and the bacteria involve in the process are called ammonifying bacteria. Then the ammonia reacts with CO2 and H2O and gives ammonium carbonate which is absorbed by plants. 4. Bacteria decompose dead bodies. They convert complex organic compounds into simple inorganic compounds. Therefore they're called natural scavengers. 5. Bacteria make the milk sour and produce flavor. They are responsible for coagulation of milk. E.g. Lacto bacillus. 6. Bacteria convert sugary substances into alcohol, acids, acetones; etc the process is called fermentation. 7. Bacteria also help to produce different types of enzymes like Amylase secreted from Bacillus, Protease from Bacillus, Streptokinase from Streptomyces. 8. Bacteria are useful for vitamin production like Vitamin B (Cabalmin) is secreted from Pseudomonas, Vitamin B (Riboflavin) is secreted from Clostridium. 9. They are important for antibiotic production like Terramycin from Streptomyces rimosus, Streptomycin from S. griseus, Neomycin from S. fradiae. 10. They are also important to produce hydrogen commercially. During the process they ferment carbohydrate and hydrogen gas is produced. 11. Bacteria decompose waste products. Harmful activities  Some of the species cause food poisoning. They secret some toxic chemical substances on out food stuff which cause food poisoning, eg Staphylococcus and Clostridium.  Some are responsible for human diseases Cholera: Vibrio cholera, Pneumonia: Staphylococcus pneumoniae Diarrohea: Escherechia coli, Tuberclosis: Mycobacterium tuberclosis Sanjaychauwal.wordpress.com

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Leprosy: M. leprae, Meningitis: Nisseria meningitides.  Some bacteria are responsible for plant diseases. Red stripe in sugarcane, Leaf streak in rice, black rot in cabbage and yellow rot in wheat are caused by Xanthomonas and Pseudomonas. CYANOBACTERIA General Characters  Mostly cyaobacteria are aquatic and some are terrestrial.  The organisms are prokaryotic. They may be unicellular, colonial.  Cell wall is composed of cellulose.  Flagella are absent. Mesosomes are absent like bacteria.  They contain photosynthetic pigments, so they are autotrophs.  No sex organs are produced and sexual reproduction is absent.  They reproduce asexually. One of the important members of cyanobacteria is Nostoc Nostoc They are found in fresh water, paddy field. The body is filamentous which is simple, unbranched, and covered by gelatinous sheath. Filament without gelatinous sheath is called trichome. Trichome is made up of small spherical or oval cells. At frequent interval there are some specialized large elongated and thick walled cells called heterocyst. The heterocyst consists of two polar nodules. The heterocyst helps to fix atmospheric nitrogen. Heterocyst is intercalary (in between two vegetative cells) but sometimes it is terminal (at the end of the filament) Reproduction Nostoc does not develop sex organs. It reproduces by asexual method. Fragmentation: when the colony breaks into small piece or fragment new colony is formed from each fragment. Hormogonia: The filament breaks into point of heterocysts. Each piece is called horomogonia and form that new colony is formed. Heterocysts: The heterocyst itself germinates and produces new filament. Sanjaychauwal.wordpress.com

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Akinetes: Under favorable condition somatic cells store food materials, which become thick walled called akinetes. They germinate to form new filament and colony.

Economic importance of Cyanobacteria  Cyanobacteria are the source of food for aquatic animals.  They also fix atmospheric nitrogen in crop growing field.  They are nutritious and decrease the alkalinity of the soil.  Some species are toxic to aquatic animals cause poison.  Accumulation of cyanobacteria in water source contaminates and pollutes water. KINGDOM - PLANTAE The organisms are autotrophic, Body is highly branched, and reserved food is starch This kingdom is divided into 3 groups Algae Chlorophyceae (Green Algae) Phaeophyceae (Brown Algae) Rhodophyceae (Red Algae) Bryophyta (Amphibious Plants) Liverworts Moss Trachophyta Pteridophyta (Vascular Cryptogames) Gymnosperms (Naked Seeded Plants) Angiosperms (Closed Seeded Plants)

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Algae Chlorophyceae  They are known as green algae  They comprise about 7000 species  They are mostly found in fresh water  They contain chlorophylls a,b

Phaeophyceae Rhodophyceae They are known as brown They are known as red algae algae

2000 They comprise about 5000 species They are both aquatic They are mostly found in and marine marine water They contain They contain carotene phycoerythrin and and fucoxanthin as phycocyanin as photosynthetic  Cell wall is made up photosynthetic pigents of outer pectose and Cell wall is made up of pigments outer alginic acid and Cell wall is made up of inner cellulose inner cellulose outer pectin and inner cellulose  They are both Sanjaychauwal.wordpress.com

They comprise species

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unicellular and muclticellular  Reserved food is stored in the form of starch.  Asexual reproduction takes place by the formation fo motile spores like zoospores and aplanospores  Sexual reproduction is isogamous, anisogamous and oogamous For eg. Spirogyra.

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They are multicellular

only

Reserved food is mannitol and lamminarin. Asexual reproduction takes place by the formation of zoospores Sexual reproduction is isogamous or aniso gamous and oogamous

They are unicellular and multicellular Reserved food is stored in the form of floridean starch. Asexual reproduction takes place by the formation of nonmotile spores like monospores Sexual reproduction is only oogamous type For Batrachospermum

For eg Fucus

eg

Spirogyra Habitat They are abundantly found in fresh water resources like ponds pools, ditches, springs, lakes, streams etc. they are widely distributed throughout the world. Structure The plant body is thalloid. The thallus is unbranched or unattached. The thallus is called filament. The young filament is attached to some substratum by the help of basal cells. Each filament consists of many cylindrical cells. The cells are longer than breadth. The cell is surrounded by gelatinous sheath. Cell wall is outermost layer, which is rigid and consists of two layers. The outer layer is made up of pectose and inner layer is made up of cellulose. Two cells in the filament are separated by a common wall, which is called septum. The cytoplasm contains cell inclusions and cell organelles. There is a central vacuole in the centre of well which is surrounded by a layer called tonoplast. The vacuole is filled by a liquid called cell sap. There is a nucleus at the centre of vacuole. In each cell, spirally coiled chloroplast is present in the cytoplasm. In chloroplast, round and spherical bodies are found which are called pyrinoid. Reproduction Sanjaychauwal.wordpress.com

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Asexual reproduction Fragmentation It is common method of vegetative reproduction. In this method, the filament may breaks up into small fragments and each such fragment grows into new filament. Akinetes Under unfavorable condition, some cells of the filament become thick walled which are called akinetes. The akinetes germinate to produce new filaments. Aplanospores The aplanospores are thin walled spores, which arise singly in the filament. The protoplast of the cell loses water and contracts. It rounds off and secrets thin wall around it to become an aplanospore. It germinates to produce new filament. Sexual reproduction Sexual reproduction takes place by conjugation method. When cells of two filaments conjugate then it is called as conjugation. There are three methods of conjugation a) Scalariform conjugation  In this method, two filaments of spirogyra come close and lie parallel to each other in opposite direction.  Two filaments get surrounded by common mucilage sheath.  The cells of the filaments produce small outgrowths towards each other, which are called papillae.  The papillae of opposite filament get enlarged and fuse together.  The common wall of papillae gets dissolve forming tube like structures, which is called conjugation tube. At this stage, it appears ladder like structure, which is called scalariform.  The protoplast of conjugating cells contract by losing water forming gametes. The gamete bearing cells are called gametangia.  The gametes of one filament move towards the cells of another filament through conjugation tube.  The migratory gametes are male gametes and stationary gametes are female gametes. Sanjaychauwal.wordpress.com

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 Two gametes fuse together to from zygote in one filament to form zygote and the zygote secretes wall around it, which is called as zygospore, but the cells of another filament, remain empty. b) Lateral conjugation  The conjugation takes place between adjacent cells of the same filament is called lateral conjugation There are two types of lateral conjugation Direct lateral conjugation  In this method, the protoplast of adjacent cells contracts by loosing water and from gametes.  In the upper protoplast a conical tube like structure is formed which is called male gamete. The lower protoplast is now called female gamete. Now male gamete penetrates common septum, move downwards and fuses with female to from zygote and then zygospore. Indirect lateral conjugation  Two adjacent cells develop small outgrowth on either side i.e. near septum, which is called papillae.  The common wall between two papillae gets dissolved and conjugation tube is formed between two adjacent cells.  The protoplast of two adjacent cells becomes contract, which is called gametes. The upper cell is called male gamete and start to move to lower cell through conjugation tube.  Now, male and lower female gamete fuse together to form zygote and the zygote secrets wall around it to form zygospore. Zygospore germination The

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filament of the zygospores decay and zygospore becomes thick walled. The thick walled zygospore sinks at the 35

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bottom of water. The diploid nucleus of zygospore undergoes meiosis division and produces four nuclei. Out of four nuclei three degenerate and one remains functional. Now the outer wall of zygospore ruptures and inner wall produce small tube called germ tube. Now the germ tube divides transversely with nucleus and septa are formed with the formation f one new filament.

Bryophyta They include 960 genera and 24000 species. They grow in moist and shady places and some are aquatic. Plant body does not bear vascular tissues and not differentiated into root shoot and leaves. They show alternation of generation that is in the life cycle two forms of the plant body are produced. Gametophytic generation  The plant body in this generation produces gametes for sexual reproduction.  The gametophytic generation is long lived.  The plant body is green; autotrophic consists of root like structures on the ventral surface called rhizoids and scales  The plant body bears male and female sex organs where male and female gametes are produced.  The male sex organs are called antheridia and the female sex organs are called archegonia.  Water is essential for fertilization.  No embryo is developed from the development of zygote. Sporophytic generation  When male and female gametes fuse together zygote is formed which develops into sporophytic plant body.  This generation is short lived.  The sporophytic plant body is differentiated into foot seta and capsule.  Within capsule of saprophyte spores are produced by meiosis division in spore mother cells. Eg. Marchantia, Funaria Sanjaychauwal.wordpress.com

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Marchantia It is one of the important species of Liverworts. It is widely distributed, commonly found in moist and shady places. There are about 65 species of marchantia. In Nepal there are three species found Marchantia palmate, M. nepalensis, M. polymorpha. Gametophyte External Structure

    

 The plant body is thalloid. The thallus is dorsoventrally flattened, prostrate, and dichotomously branched.  On the dorsal surface there is dark green colored mid rib.  The mid rib bears gamma cup for asexual reproduction  The ventral surface consists of unicellular, tubular, colorless structures called rhizoids and multicellular plate like violet in colour structures are present called scales. The rhizoids absorb water. They are of two types o Smooth rhizoids which are thin walled. o Tuberculate rhizoids which are thick walled The scales protect from the injuries to the thallus and transport water. The scales are simple and complex. At the apex of the thallus there is apical notch. The male and female plants are found separately i.e. dioecuious. In male plant male sex organs, Antheridia are produced and in Female plant female sex organs, archegonia are produced.

Internal structure  On the dorsal and ventral surface of the thallus outermost single layered epidermis is present. Sanjaychauwal.wordpress.com

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   

The upper epidermis consists of air pores The air chambers are present below upper epidermis. The air chambers are separated by partition walls. In air chamber there are photosynthetic filaments which are made up of cells which are rich in chloroplast where food is synthesized. It is synthesizing zone.  Below synthesizing zone, there is a region of compactly arranged paranchymatous cells, which are thin, walled that store food. It is storage zone.  Lower epidermis consists of number of rhizoids and scales.

Reproduction By fragmentation In this older region of thallus decayed or degenerate and younger region or apical region again regenerate and produce new plant body. By adventitious branches In this method, branches develop on the ventral surface of thallus. Now branch grows into new plant body. By gemmae The cup like structures is found on the midrib of dorsal surface. Within gemma cup small stalked structures are formed called gammae. The gammae are asexual reproductive structures, which are made up of parenchymatous cells. On the lateral side of gemmae notch is present. The cells of the gammae are filled with chloroplast. When the gemmae fall on the ground, they produce new plant body. Sexual Reproduction The Marchantia is dioecious or heterothallic i.e. male and female sex organs are found in separate individual. The male sex organ is found in male plant and female sex organs are found in female plant. The sexual reproduction takes place by fusion of male and female gamete. Male gametophyte  The male gametes are called antherozoids. Each antherozoid is elongated, coiled, and flagellated. Anhterozoids are formed within male sex organ called antheridium. Each antheridium is globular with short stalked and jacket layer encloses Sanjaychauwal.wordpress.com

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numerous cells called androcytes.  Each androcytes forms antherozoids when antheridium gets ruptured and therozoids liberate out. The antheridia are fond on the upper surface of the receptacle of antheridiophore.  Each anterridium is embedded in a cavity. The cavity opens outside through a pore called ostiole. The antherozoids come out through ostiole and swim in water. Female gametophyte  The female plant bears archegoniophore. It is 5-7 cm long. It consists of stalked and star like female receptacle. Usually receptacle has nine rays of star like structure.  Numerous female sex organs called archegonia are hanging in lower part of female receptacle.  Archegonia consists swollen basal portion called Venter and elongated neck.  The Venter consists of a prominent cell called egg. Near egg, there is another cell and Venter canal cell. Cell in the neck are called neck canal cell. Fertilization Swimming antherozoid reach to the archegonia tip with the help of water. Neck canal cell of archegonia gets dissolved. A kind of mucilage is secreted by dissolving neck canal cells and reaches to the venter canal cell and gets fused with egg and zygote is formed. Sporophyte

 The zygote undergoes number of cell division during development and the structure of zygote at that stage is called sporophyte.  The basal portion of the sporophyte is called foot and middle elongated portion is called seta.  Round globular terminal part is called capsule which consists of thread like elaters and number of unicellular spores formed by meiosis division in spore mother cells within capsule.  The capsule is surrounded by a layer called jacket.

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 The whole sporophyte is surrounded by layer of cell called calyptra. Elaters help in spore discharge when jacket or capsule is ruptured.  The sporophyte is parasitic because it depends up on female gametophyte.  Half of the spores germinate produce male gametophyte and half germinate to produce female gametophyte.

Funaria It is cosmopolitan in distribution, mostly found in moist soil, rock, walls, and tree trunks. Gametophyte External structures Plant is small about 1-3 cm long, stem is erect and branched. It is differentiated into rhizoids, axis, and leaves. The rhizoids are multicellular and branched. The axis is aerial, erect, and branched. The leaves are simple, small, and spirally arranged. The upper leaves are large and lower leaves are crowded. Intenal structure Stem: The outermost layer is epidermis contain chloroplast. Below the epidermis there is multilaered parenchyma called cortex. In the centre there is compact and narrow cells without protoplast called central cylinder which factions as conducting tissue. Leaves: The leaf lamina consists of single layered parenchyma rich in chloroplast and the midrib contains central strand.

Reproduction Asexual method of reproduction takes place by following method Sanjaychauwal.wordpress.com

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By primary protonema: The spores germinate to give rise small filament called primary protonems, which contains small buds from where new plant is produced. By secondary protonema: The filament can grow from stem, leaves, or rhizoids called secondary Protonems. They bear small buds and which are capable to give rise new plant. By gemmae: The small multicellular structures develop on leaves and axis, which develop into new plant. By bulbil: The gammae like structures developed on the rhizoids are called bulbils which grow into new plant. Sexual reproduction Funaria is monoecious female organs develop or separate branch of same plant autocious. Male branch - the branch with male sex organs id called male branch.  The male sex organs - Antheridia develop in group at the apex of shoot  They are mixed with hair like structure paraphysis.  Antheridia and paraphysis are surrounded by leaves called perichaetial leaves. Each antneridiuim is stalked, club-shaped, surrounded by jacket; two apex cells are large/thick called operculum. With the help of water, the operculum ruptures and androcytes come out and change into antherozoids (spermatozoids). Female branch – The branch with female sex organs.  The female sex organ – Archegonia are developed at the apex of shoot.  The archegonia are mixed with hair like sterile structures called paraphysis.  Both surrounded by perichaetial leaves. Each archegonium is flask shaped, stalked, and contains broad Venter and long neck. The Venter contains an egg, Venter canal cell, double layered wall. Neck contains neck canal cells. Fertilization

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In pressure of water antherozoid reach to archegonia tip. Neck canal/Venter canal cells degenerate. antherozoids enter through neck and only one free with egg to form zygote. Sporophyte The zygote secrets thick wall around it called oospore, which grows into a saprophyte. The mature saprophyte consists of foot\seta\capsule  Foot – it is barrel, conical shaped, embedded in apex of a branch.  Seta – it is very long, twisted, and slender.  Capsule- pear shaped in structure and it consists of o Apophysis – it is multicellular thick basal portion of the capsule o Columella- it is central portion of the capsule surrounded by spore sac. o Spore sac- it is a sac containing spores on either side of columella. On the outer side of the spore sac air spaces are present separated by partition wall. o Operculum – apical region of capsule. It is conical lid of the capsule. It consists of small teeth called peristome. Dehiscence of capsule At maturity annulus breaks and the operculum is thrown away. The spores are liberated out. Spore germination Under favorable condition the spore, germinate to produce small filament. The filament branches freely called primary protonema. The primary protonema gives small buds. Each bud gives rise into new Funaria plant. Gemmae Secondary protonema

Primary protonema Bulbil

Gametophyte Male branch Antheridia

Female branch

Primary protonema Spores

Archegonia

Antherozoids Ovum (egg) Sanjaychauwal.wordpress.com Zygote

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Pteridophyta They are truly land plants that grow well in moist shady cool places. The plant body is sporophyte, which is differentiated into leaf stem and roots. The sporophyte is the dominant stage in the life cycle. Which is completely independent attheadult stage? They are well-developed vascular plants therefore; they are also called vascular cryptogams. The spores on germination give rise to gametophytic phase, which is short lived. The gametophytic phase is autotrophic and independent. The water is essential for fertilization. Alternation of generation takes place. Fern (Dryopteris) Habitat Sanjaychauwal.wordpress.com

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Commonly found in moist and shady places in tropical to temperate region. Some are fond in aquatic habitat as epiphyte i.e. growing on trunk of trees. Sporophyte External structure  The plant body is sporophytic and differentiated into root, stem, and leaf. The root is fibrous and arises from stem. The roots are short lived and therefore called ephemeral and branched.  The stem is underground horizontally placed, branched or unbranched. Its colour is dark brown. It is called rhizome. It is covered by brown hairs called remanta which protects young leaves from the injury and drying.  The leaf is aerial part. It consists of thick and stout petiole. On the either side of rachis, pinnae are present. The young leaves are curved and called circinate leaves. Internal structure Root  Transverse section of root shows that the outermost layer of root is epidermis. In young root hairs are present. Below epidermis, there is multilayered broad region of cortex, which is differentiated into two regions.  Outer cortex is made up of thin walled parenchyma, which stores food, and transport water.  Inner cortex is made up of thick walled sclerenchyma, which gives mechanical strength to the root.  Below inner cortex, there is single layer of barrel shaped cells called endodermis containing chloroplasts. It stores and forms starch.  Endodermis is followed by pericycle, which is composed of compactly arranged one, or two layers of thin walled cells. There is a vascular cylinder surrounded by pericycle. It has xylem and phloem. There are two large sized metaxylems and on either side of metaxylem small protoxylems lie at two sides. Both xylems are surrounded by phloem. Stem  The outer most layers are single layered called epidermis. The epidermis is covered outwardly by a layer of non-living materials called cuticle. Below epidermis, there is multilayered broad region of cortex, which is differentiated into two regions. Sanjaychauwal.wordpress.com

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 Outer cortex is made up of thick walled sclerenchymatous cell, which is called hypodermis. It gives mechanical support to the plant.  Inner cortex is made up of thin walled parenchymatous which stores food.  Below cortex vascular bundle is s dictyostele, which consists of a hollow and cylindrical many vascular bundles called meristeles. Each meristele has its own endodermis, pericycle, phloem, and xylem.  The region between the meristele is called pith.  Endodermis is the outer most layers made up of barrel shaped cells. Below it layer of thin walled parenchymatous cells present called pericycle.  The xylem and phloem are surrounded by pericycle and either side of metaxylem protoxylem lies. The phloem surrounds the both xylems. Petiole  The outer layer is single layer cell called epidermis. It is surrouded by a layer of cuticle. Below epidermis, there is a few layer of thick walled sclerenchymatous cell called hypodermis. The hypodermis is followed by thin walled parenchyma, which is called inner cortex.  The vascular bundle is dissected into number of vascular cylinders so called dictyostele. Each vascular cylinder is called meristele having own endodermis, pericycle, xylem and phloem. The region between the meristele is called pith. Reproduction  The fern plant is sporophytic that produces spores. The spores are unicellular uninucleated thick walled and dusty appearance. The spores are produced within sporangia. Each sporangium has a short stalk and capsule covered by single layer of cells called jacket.  The capsule has some flat cells called annulus and a demarcation for break called stomium. The spores are formed within capsule. In dry condition annulus contract, loosing water and sporangium or capsule ruptured through stomium and spores are released out.  Sporangia are found in a group. The group is called sorus. Sori are found on the ventral surface of pinnae. Pinnae, which bear sori, are called sporophylls.  The sori usually dark brown in colour and are round Sanjaychauwal.wordpress.com

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patches arranging on ventral leaf surface. The sporangia are arranged on either side of placenta and are covered by indusium. Spore Germination  Under favorable condition in soil, spores germinate by producing small tube called germ tube. The germ tube undergoes mitotic division to form uniseriate filament.  Rhizoids are developed at the base of uniseriate filament. Uniseriate filament undergoes multiple divisions and develops into heart shaped structures called prothallus. Mature prothallus bears rhizoids at the base on ventral surface. Gametophyte  The prothallus produced by germination of spore is called gametophyte, which forms male and female sex organs.  The male sex organs - Antheridia and female sex organs - archegonia are also found developed on the ventral surface of the prothallus. The archegonia are situated below apical notch and the anheridia are situated on the posterior end of prothallus.  The mature prothallus is green small multicellular and dorsoventrally flattened. Sexual reproduction  The prothalus is monocuous. The antheridia are small, globular, and sessile.  The antheridia remains covered by layer called jacket, which encloses about 32 spermatozoites out of which only one fuse with egg.  Each spermatozoites are coiled multiflagellated with posterior vesicle. Vesicle helps to swim in water. The spermatozoites or male gametes come out when anteridial wall gets ruptured.  The archegonia are small flask shaped and multicellular. The neck of archegonia consists of one binucleate neck canal cell and the Venter consists of one Venter canal cell and egg or ovum. Fertilization The spermatozoites reach to the apex of archegonia by swimming in water. The spermatozoites get the way Sanjaychauwal.wordpress.com

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through neck when the neck canal cell and Venter canal cell dissolved and fused with egg. The zygote is formed which is diploid. The zygote undergoes multiple divisions and develops into embryo. Form embryo root stem and leaves develop and new fern plant is produced. From the anterior superior region stem arises leaves arise from anterior inferior region and root arises from the posterior region. After development of embryo, the prothallus decays, and gametophytic generation is finished.

Gymnosperm General characters Gymnosperms are exposed seeded evergreen plants. They are considered as the earliest plants on the earth after pteridophyta .there are about 70 genera and 725 species. The plant body is sporophytic and differentiated in to root stem and leaves. They are heteroporous. Pinus (Sallo) Kingdom – planate Division- trachaephyta Sub division- gymnosperm Class- coniferopsida Order – coniferales Family –pinaceae Genus- Pinus Habitat Usually it is found in temperate dry habitat. I.e. inner range of Himalayas in Nepal .But grows through the Northern Hemisphere. It forms dense evergreen forest. Morphology It is long, evergreen, perennial tree. Young tree of pinus gives a Sanjaychauwal.wordpress.com

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pyramidal appearance. The plant is saprophyte, it is differentiate in to root, stem and leaves. Root The root is well-developed tap root system but does not grow very deep in soil. The taproot produces lateral root, which grows extensively. The root hairs are poorly developed root tap is covered by protective root cap. Root is covered by a kind of fungi called mycorrhiza. If it is not present, pinus dies. The relationship between the fungi and root is called symbiotic relation. Stem The stem is erect, aerial, cylindrical, woody, branched. Branches are dimorphic i.e. there are two types of branches in stem. Long branches and Short branches The branches, which come from the main trunk, are called long branches. They show unlimited growth. Lower long branches are longer and upper long branches are shorter. Therefore, the plant appears as pyramid like. The branches, which come from the main trunk and from long branches, are called short branches. They are very short they show limited growth. Short branches terminate into a cluster of green needles like leaves. Short branches are replaced in every 2or 3 year. Leaves The leaves are also dimorphic. There are two types of leaves.  Foliose leaf  Scaly leaf Foliose leaves: - they are green, long needle like they arise from short branches. They take part in photosynthesis. On the basis of number of leaves, the species are of following types. Short branches having one foliose unifoliar spur P. monophyla Short branches having two foliose bifoliar spur P. murkurii Short branches having three foliose trifoliar spur P. roburgtaii Short branches having four foliose qoadrifoliar spur P. quadrifolia Short branches having five foliose pentafoliar spur P. wallichiana Scaly leaves: - they are scale like no green, dark brown in colour and are thin. They arise from short and long branches. They protect stem or branches by covering.

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Reproductive Structure Pinus is monocious. The male and female reproductive structures are called strobili or cone. They are produced in different branches of same plant. MALE CONE  They are formed in group behind apical bud of long shoot or Long Branch.  They are small, 2-4 cm long and oval in shape.  The central axis of male cone is surrounded by spirally arranged microsporophylls.  There are about 60-150 microsporophylls in each male cone. Microspores (Pollen grains)  At the base of each microsporophylls there are two sac like structures called microsporangia.  Within each microsporangium, numerous spores are formed called microspores.  When microsporangial wall bursts, the spores or pollen grains come out and appears yellow mass called shower of sulpher. Male gametophyte  The male gametophyte is formed from microspores.  The microspores are uninucleate, thick walled having two wings.  The microspores are surrounded by three layered wall exine, exointine and intine. The exointine expands to form wings.  Within microsporangium, microspore divides to form four celled stage microspore.  After pollination, a tube called pollen tube is developed from four celled microspore. Within pollen tube two male gametes are produced form generative cell. FEMALE CONE  The female cones are formed in-group of 1-4 and towards the tip of the long shoots.  They are larger than male cones i.e. 15-20 cm.  The central axis of female cone is also surrounded by spirally arranged megasporophylls. Megaspore  At the base of megasporophylls ovules are produced.  Lower few megasporophylls are sterile having no ovules.  Each megasporophyll consists of small membranous scales Sanjaychauwal.wordpress.com

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called bract scales and large, thick, hard, and triangular scales attached on the dorsal side of bract scale called ovuliferous scales.  At the base of ovuliferous scale, two ovules are present on the dorsal side.  Within the ovule the megaspore is developed. Female gametophyte  It is formed from megaspore within ovule.  The megaspore divides multiple times to form female gametophyte.  Archegonia are formed form peripheral cells towards micropylar region of female gametophyte.  Each archegonium consists of 8 celled neck, one Venter canal cell and one larger egg. Fertilization After one year of pollination, fertilization takes place. Zygote is formed and then developed into embryo. The embryo consists of more than two cotyledons. New ovule is transformed into seed. Under favorable condition, seeds fall down and new plant germinates.

ANGIOSPERMS Family 1 : Cruciferae The cruciferae is also known as mustard family. This family includes 375 genera and 3200 species. The plants are found abundantly in northern hemisphere and distributed worldwide. This family includes vegetables flowers and wild varieties. Sanjaychauwal.wordpress.com

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Some economically important plants of this family are Brassica compestris, (TORI) Important for oil and vegetable B. rapa, (Turnip) Important for vegetable B. nigra, (RAYO) Important for oil and vegetable B. oleracea, (CAULI) Important vegetable and Anticancer Raphnus sativus (MULA) Important vegetable Lepidium sativum (CHAMSUR) Important vegetable Habit habitat: Annual or biannual or sometimes perennial, herbs, rarely shrubs, wild or cultivated, terrestrial, mesophytic. Root: Tap root and branched or modified (fusiform e.g. Raphnus sativus, Napioform e.g. B.rapa), sometimes adventitious e.g. Roripa. Stem: Erect, herbaceous, branched, cylindrical, solid, hairy or glabrous, green, sometimes stem is condensed or thickened (B. oleraces, R. sativs) Leaf: Exstipulate, petiolate or sessile, alternate, rarely opposite, simple, cauline and ramal or radical, lyrate, lobed or entire, acute, glabrous, unicostate, reticulate venetation. Inflorescence: racemose, receme or corymb Flower: Ebracteate, ebractiolate, pedicellate, hermaphrodite, complete, actinomorphic or zygomorphic, hypogynous, tetramerous, small, white or yellow. Calyx: sepals-4, polysepalous, sepaloid, sepals in two worls, 2 in each whorl, hairy or glabrous, imbricate aestivation. Corolla: petals-4, polypetalous, cruciform, each petal consists of limb and claw, alternate with sepals, petaloid, valvet or imbricate aestivation. Androecium: stamens-6, tetramerous, polyandrous. Anther – bicelled, dithecous, basifixed, introse Gynoecium: Carpels-2, bicarpellary, syncarpous. Ovary - superior, unilocular or bilocular, placentation parietal. Style – short. Stigma – bilobed or glabrous. Fruit: Siliqua Seed: Dicotyledinous and non-endospermic Floral formula: Systemic position Kingdom Plantae Division Angiosperm Sanjaychauwal.wordpress.com

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Class Subclass Series Order Family

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Dicotyledonae Polypetalae Thalamiflorae Parietals Cruciferae

Distinguishing characters Herbaceous stem, alternate leaves, racemose inflorescence, ebracteate, tetramerous, sepals – 4, polysepalous, Petals – 4, polypetalous, cruciform, stamens – 6, tetradynamous, fruit is siliqua. Family 2 - Solanaceae This family is also called as potato family. There are about 90 genera and 2200 species. This family is distributed in tropical to temperate region world wide. Some are cultivated and others are wild. Some economically important members are Solanum tuberosum (potato), important vegetable S. melongena (Brinjal), important vegetable S. nigrum (Black night shade), important medicinal plant of Jaundice and fever Lycopersicum esculentum (tomato), important vegetable Capsicum annum (chilly), important spices Nicotiana tobacum (tobacco), important for tobacco, and alkaloid Datura stramonium (Dhaturo), important medicinal plant and sedative Habit/Habitat: Annual rarely penennial, herbs, rarely shrubs and soft trees (S gigantium), some are climbers (S. dulcamera), mesophytic. Root: Tap root, branched, sometimes adventitious Stem: Erect, rarely prostrate or climbers, branched, herbaceous or woody, solid or fistular, cylindrical, glabrous or spinous, green, sometimes underground (S. tuberosum) Leaf: Exstipulate, petiolate or sub-sessile or sessile, alternate or opposite, cauline and ramalo, simple ro compound, ovate, entire, acute, glabrous or hairy, unicostate and reticulate venation. Inflorescence: Cymose, axillary cyme or terminal cyme Sanjaychauwal.wordpress.com

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Flower: commonly ebracteate, ebractiolate, pedicellate or subsessile, actinomorphic, rarely zygomorphic, complete, hermaphrodite, pentaerous, hypogynous, flower small, white, or pink in colour. Calyx: Sepals-5, gamosepalous, sepaloid, toothed or lobed, campanulate, hairy or glabrous, valvate aestivation. Corolla: Petals – 5, gamopetalous, petaloid, campanulate or funnel shaped, sometimes tubular or rotate, valvate aestivation or twisted or imbricate, pink or white or purple in colour. Androecium: Stamens – 5, polyandrous, sometimes stamen – 4 or 2 or staminode, epipetalous. Anther - bilobed, introse, basifixed. Gynoecium: Carpel;s – 2, bicarpellary, syncarpous. Ovary – superior, bilocular or tetramerous, axile placentation, many ovules in each locule. Stigma – lobed or capitate. Style – long and single Fruit: Berry or capsule Seed: Dicotyledonous, endospermic Floral formula: Floral Diagram Systemic position Class Dicotyledenae Subclass Gamopetalous Series Bicarpellate Order Polymonials Family Somalanceae Diagnostic characters Leaves alternate, simple or compound, inflorescence cymose, flowers pentamerous, actinomorphic, hypogynous, sepals – 5, gamosepalous, petals – 5, gamopetalous, Stamens – 5, polyandrous, epipetalous, Carpels – 2, syncarpous, axile placentation, Fruit berry or capsule.

Family 3 : Liguminosae Sub family: Papilionaceae Sanjaychauwal.wordpress.com

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Papilionaceae is also known as pea family. There are about 600 genera and 1300 species. Widely distributed,abundant in trophical to temperate region. Some economically important members are Pisum sativum, PEA - important pulse (DAL) Phaseolus vulgaris, BODI - important pulse (DAL) Vicia faba, BAKULLA - important pulse (DAL) Gycine max, BHATMAS - - important pulse (DAL) Arachis hypogea, BADAM - Important for oil and nut Cicer arientum, GRAM - - important pulse (DAL) Cajanus cajan, ARHAR - important pulse (DAL) Delbergia sisso, SISSOO - Important timber Lens culinaris, MASURO - important pulse (DAL) IIkHabit Habitat: Annual herbs or perennial shrubs or trees, some are climbers, cultivated or wild, usually mesophytic. Root: Tap root and branched, root nodules are present which is important for nitrogen fixation. Stem: Erect or prostrate or climbing, herbaceous or woody (Dalbergia sissoo), branched, angular or cylindrical, solid or fistular, glabrous, green. Leaf: Stipulate, cauline and ramal, simple or compound, pinnately compound, modified into tendrils, alternate or opposite or sometimes whorled, ovate, entire, acute or mucronate, glabrous, green or glaucous, unicostate, reticulate venation. Inflorescece: Racemose, receme or panicle or spike or solitary Flower: bracteate or ebracteate, ebractiolate, pedicellate, complete, zygomorphic, hermaphrodite, pentamerous, papilionaceous, hypogynous or perigynous, white or pink in colour Calyx: sepals – 5, gamosepalous, toothed or bilabiate, sepaloid, campanulate, valvet or imbricate aestivation. Corolla: Petals – 5, polypetalous, petaloid, papilionaceous, one petal large, two medium and two small, fused called keels, vexillary aestivation. Androecium: Stamens – 10, diadelphous or monoadelphous, rarely polyandrous. Anther: bilobed or dithecous, basifixed or dorsifixed, intorse. Gynoecium: Carpel – 1, monocarpellary. Ovary: superior, unilocular, marginal placentation. Style – curved. Stigma – capitate or hairy. Sanjaychauwal.wordpress.com

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Fruit: Legume or pod Seed: Dicotledonous and non endospermic. Floral formula Floral diagram Systemic Position Class Dicotledonae Sub Class Polypetalae Series Calciflorae Order Rosales Family Leguminosae Sub Family Papilionaceae Diagnostic characters Leaves – stipulate, alternate or opposite, simple or compound. Inflorescence racemose, Flower – pentamerous, zygomorphic, hermaphrodite, papilionaceous, hypogynous or perigynous. Sepals – 5, gamosepalous, Petals 5, polypetalous, papilionaceous, Stamens – 10, diadelphous, Carpel – 1, monocarpellary, Fruit legume or pod Family 4 - Compositae The compositae family is also known as sunflower family. This is the largest family of angiosperm. There are about 1000 genera and 2300 species. They are cosmopolitan in distribution. Some economically important members are: Helianthus annus, SUNFLOWER - Important for oil Chrysanthamum indicum, CHRYSANTHAMUM - Important ornamental flower Tagetes erecta, HAJARIPHOOL - Important ornamental flower Artemesia indica, TITEPATI - Important medicine for skin disease and antihelminthic Azeratum conyzoides, GANDHE - important medicine for cut and wound Carthamus tinctorius. KUSUM - important medicine

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Habit/Habitat: Mostly they are annual herbs or perennial shrubs, some are climbers, wild or cultivated, ornamental, few are trees (Veronica arborea), hydrophytic, mesophytic or xerophytic. Root: Tap root, branched or adventitious Stem: Erect or prostrate, few are climbing, herbaceous or woody, solid or fistular, branched, cylindrical or angular, hairy or glabrous, sometimes underground or stem unbranched. Leaf: Exstipulate or stipulate, petiolate, cauline and ramal, alternate or opposite or whorled, simple or compound, pinnately compound, alnceolate, serrate or entire, acute, unicostate, reticulate venation, sometimes leaves are modified into spines or reduced. Inflorescence: Head or capitulum, Head consists of two teyps of flowers Ray florets and disc florets, Head is surrounded by involucre of bracts Flowers: Ray florets bracteate, ebracteolate, sessile, zygomorphic, unisexual, incomplete, epigynous, ligulate Calyx: Rudimentary, sometimes absent or hairy or scaly Corolla: Petals – 3-5, gamopetalous, bilabiate, valvet aestivation. Androecium : absent Gynoecium: carpels – 2, bicarpellary, syncarpous, Ovary – inferior, unilocular, basal placentation, Style – Single, Stigma – bifid Fruit: Cypsela Seed: nonendospermic, dicotyledonous Floral Formula Floral diagram Disc Florets Bracteate, sessile, ebractiolate, actinomorphic, hermaphrodite, pentamerous, epgynous, sometimes unisexual. calyx: Reduced or absent or sometimes hair like or scale like – 2-5. Corolla: Petals – 5, gamopetalous, tubular, bilobed, valvet aestivation. Androecium: stamens – 5, polyandrous, syngenesious, epipetalous, Anther – dithecus, basifixed, introse. gynoecium: Carpels – 2, bicarpellary, syncarpous, Ovary – inferiorm unilocular, basal placentation, Style-long, Stigma-bifid. Sanjaychauwal.wordpress.com

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Fruit: cypsela Seed: dicotyledenous, nonendospermic Floral formula Floral diagram Systemic position: Class Dicotyledonae Subclass Gamopetalous Series Inferae Order Asterales Family Compositae Diagnostic characters: Leaves simple or comound, opposite or whorled. Inflorescence Head or capitulum. Flower - bracteate, epigynous, Two types-ray and disc florets. Sepals rudimentary or hairy or scaly, 2-5. Petals – 2-5, gamopetalous. Stamens absent in ray florets but stamens – 5 in disc florets, polyandrous, syngenesious. Carpels – 2, bicarpellary, syncarpous. Ovary – inferior, uniclocular, basal placentation, Stigma – bifid. Family 5 – Graminae (Poaceae) The Graminae family is also known as grass family. There are about 530 genera and 5200 species. They are widely distributed, Some economically important members are: Triticum aestivum, WHEAT - Important cereal crop Oryza sativa, RICE - Important cereal crop Zea mays, MAIZ - Important cereal crop Cynodon dactylon, DUBO - important religious and medicinal plant Saccharrum officinarum, SUGARCANE - Important for sugar Bambusa arundinaceae. BAMBOO - Important medicinal and wood plant Habit/habitat: Annual herbs or sometimes perennial shrubs, mesophytic, wild or cultivated. Root: Fibrous root and branched or adventitious Sanjaychauwal.wordpress.com

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Stem: Erect or prostrate, runner, aerial, herbaceous or woody, fistular or solid, cylindrical, glabrous or hairy, branched or unbranched. Leaf: Exstipulate, sessile, simple, alternate, leaf is divided into two parts. Lower part is thick leaf sheath, which covers internode, and upper part is thin leaf blade. Its inner surface is glabrous and outer is rough or hairy. At the base of blade, there is a membranous colourless hairy structure called lugule and two sickle shaped structures called auricle. Leaf blade is long narrow, lanceolate, acute or accumunate, parallel venation. Inflorescence: Spike or panical of spikelet. Each spikelet consists of sterile bract called glume. Each glume is boat shaped with thick mid nerve. Flowers: Bracteate, sessile, incomplete, hermaphrodite, rarely unisexual, sygomorphic, hypogynous. Each flower consists fo two covers the outer lemma and inner palea. The lemma bears stiff thread like outgrowth called awn. The lemma and palea encloses androecium and gynoecium. Perianth: When calyx and corolla is not differentiated then it is called perianth. It is represented by two or three membranous lodicules. Androecium: Stamens 3 or 6, polyandrous. Anther – dithecus, versatile Gynoecium: Carpel – 1, monocarpellary, sometimes carpels – 3, tricarpellary, syncarpous. Ovary – superior, unilocular, basal placentation. Stigma – feathery and bifid Fruit: caryopsis Seed: endospermic, monocotyledonous Floral formula Floral diagram Systematic position Class monocotyledonae Series: Glumaceae Family: Graminae Diagnostic Charaters Root - adventitious or fibrous. Stem - erect and cylindrical. Leaves narrow, lanceolate, parallel venation and consisting of leaf sheath and leaf blade. Inflorescence - spike of spikelets. Perianth is represented by 2 or 3 lodicules. Stamens – 3 or 6, polyandrous. Anther dithecus, Sanjaychauwal.wordpress.com

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versatile, Carpels – 1 or 3, syancarpus, Ovary superior, basal plancentation, stigma feathery and bifid, fruit caryopsis.

BIOTA AND ENVIRONMENT FOREST RESOURCES The forest is very important renewable natural resources. About 37% land area of Nepal is occupied by forest. But according to unofficial record only 10% land area is occupied by forest. Importance of forest  The source of raw materials  It provides timber fire wood which are used for various purposes like furniture, building houses etc it also provides fodder, different type of products like resin gum fiber tubers etc.  In Nepal fuel wood is only the source of energy for domestic cooking purpose.  The forest is being used as ayurvedic medicines drugs spices insecticides etc also used for extracting essential oils, which are used in soaps and cosmetics.  Various industries depend on forest for their raw material like paper plywood factories tanning materials like dyes gums resin obtained from plants are used in many industries  The forest plays a significant role in keeping the atmospheric balance by consuming coarbondioxide releasing oxygen. It also control pollution  The green plants are the primary source of energy for the other biotic components  The forest checks soil erosion and land degradation. The roots hold the soil. The forest stops the soil being eroded away by strong winds or rains.  The forest provides shelter to varieties of plats animals and microorganism.  Large numbers of people visit the forest for peace, beauty, and recreation. It provides natural beauty. Sanjaychauwal.wordpress.com

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Types of forest in Nepal The forest of Nepal is classified on the basis of geographical location and climatic characteristics. Tropical forest: The forest found below 1000 meter from the seal level is tropical forest. It is found in terai belt. The forest of this belt is also called as Dun or Bhavar. The main forest is Sal Forest (Shorea robusta), Reverine, Decidious or evergreen forest is also found in this belt Subtropical forest: the forest present between 1000 to 2000 meters from the ea level is subtropical forest. Below mahabharat range the Alnus, Schima, Pinus and Castanopsis forest are found in this belt Temperate forest: the forest present between 2000 to 3000 meters from sea level is temperate forest. This range is also called mahabharat range, foothill, or lower Himalayan range. The Pinus, Rhododendron, Brich forest are found in this belt. Usually broad leave evergreen forest are found. Sub alpine forest: the forest present between 3000 to 4000 meter from ea level is subalpine forest. This belt is also called as above mahabharat range or Himalayan range. Rhododendron, Birch, Silver and Fir Forest are found. Alpine Forest: the forest present between 4000 to 5000 form the sea level is alpine forest. This range is also called as a high Himalayan range. Juniperous, Rhododendron forest are found in this zone AFORESTATION Plantation and selection of useful species, removal of undesired species, care, management and protection of forest, implementation of laws, utilization of forest education and activating the community and the people is called a forestation DEFORESTATION It is characterized by loss or cutting of forest trees which brings s series of unfavorable changes in the whole biosphere. In the world 20.4 billion hector, forest is destroying per year. Among high rate of deforestation Nepal is one. 2.8 billion tons of CO2 is added in atmosphere per year by deforestation. In Nepal during 1965 to 1979, every year 70000 hector forest was destroyed. After 1979, every year 12000 hector forest was destroyed. After 2046 BS. 1200 hector forest was declared.

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Causes of deforestation  Over production:  Due to over population of both human and livestock, demand for rood space, agricultural land increases which lead over exploitation of forest.  Due to fire in forest, several seed and seedling destroyed. In total 30% fire is man made.  Forest trees are overgrazed by domesticated animals  Agricultural cultivation is encroaching forest land. It is being extended at the cost of forest.  Construction of roads, dams, urbanization, and mining lead to deforestation.  Pests and diseases also cause deforestation. Hazards of deforestation  Soil erosion, flood, landslide occurs frequently.  Due to deforestation, natural resources are also destroyed.  Due to soil erosion fertile soil with organic contents are washed away. This cause declination of fertility of soil.  It adversely affects the climate, oxygen and carbondioxide contents and rainfall. It leads to global warming.  Destruction of wild life due to loss of forest their shelter is destroyed.  Shortage of forest products and increase in pollution  Desertification FOREST MANAGEMENT  A forestation or reforestation programs both at governmental and local levels should be launched.  The community forest programs are implemented under the management and supervision of local communities.  The private forest programs are also implemented.  Modern techniques for the pests control and management should be added to save forest.  Agro forestry on marginal and sub marginal farm land.  Alternative sources of energy should be employed  Herbal farming should be extended for increasing the production of herbs.  Public awareness and education should be launched. Sanjaychauwal.wordpress.com

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ECOLOGICAL IMBALANCES 1. Green House Effect The higher concentration of carbon dioxide may act as a serious pollutant. The carbon dioxide layer present in the atmosphere function like the glass panel of the green house which allow the sun light to pass through but prevent the heat from being re radiate in outer space. This is called green house effect or atmospheric effect. Thus, increase carbon dioxide level tends to warm the air, which is called Global Warming. Bout 100 Years ago the concentration of CO2 was 275 ppm. Now it is 350ppm and by the year 2040, it is expected that it will reach to 450 ppm. Causes of increase in CO2 Due to human civilization, excessive amount of CO2 is being deposited in the atmosphere through furnaces of power plants automobiles factories burning of coal or fossils fuels. To some extent on increase in CO2 level in atmosphere increases the rate of photosynthesis but further increase pollutes the air and water. There are other gases also which cause green house effect they are CO SO2, NO2, CH4, and CFCs Effect of Global Warming Green house effect results global warming which causes more floods due to melt of ice and the sea level increases. More hurricanes and cyclones occur. If the total ice of earth melt then 200 ft of water would be added to the ocean surface. A rise in sea level of 50-100 cm would flood low lands of Bangladesh and West Bengal. Within 25 years, there will be rise in sea level by 1.3-3.5 m. Then only from Bangladesh alone 15 million people will have to move. Dhaka and Calcutta may be inundated. A rise of 50C temperature of earth raises the sea level by 5m within few decades. Higher atmospheric temperature would increase evaporation of water from the farms thus reduce the crop yield. 2. Depletion of Ozone Layer The ozone is a gas (O3) occurs naturally in earths atmosphere between 10-50 Km. the ozone is considered as both destroyer as well as protector for us. The ozone as a destroyer Sanjaychauwal.wordpress.com

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High concentration of ozone reduces crop yield, damage leaves reduces quality of crops. 0.3-ppm ozone causes throat, nose irritation, 1.3 ppm causes fatigue, and 9 ppm causes several pulmonary diseases. Ozone as protector The ozone layer prevents UV rays coming from sun to the earth. 10% reduction of O3 increases UV radiation on the earth by 2%. It causes skin cancers. 10% reduction of ozone leads 20-30 % increase skin cancer. Only in America 6000 people per year die by skin cancer What is Ozone? The accumulation of oxygen in the atmosphere due to photosynthesis by green plants resulted in the formation of an ozone layer high in the earth atmosphere. The ozone layer forms a very protective covering around the earth's atmosphere. It prevents the UV rays present in the solar radiations from reaching our atmosphere, thus saving us from the extremely damaging effect of UV rays. The Ozone layer depletion is the process of destruction or using up of ozone in the stratosphere by different pollutants making the ozone layer thinner. when ozone is depleted there would be certain zones or holes without ozone through which UV radiation enter the earth causing various problems such zone or hole called ozone hole. Cause of Ozone depletion Chlorofluorocarbon (CFC) and nitrogen oxides produced by the air craft, satellites, industries, and fertilizers release in atmosphere and specially CFCs stays for five to six years in the atmosphere. During this period, it gradually releases chlorine, which reacts with ozone and causes damage to it. CFCs…………………..Cl + C-compounds O3 + Cl………………...ClO + O2 ClO + O………………Cl + O2 Effect of ozone layer depletion Change of environment, due to more UV radiations entering in the earth rises to a certain degree, which can lead to the failure of rainfall. When the ozone layer is depleted, harmful UV radiations may cause skin cancers. A higher UV radiation reduces the photosynthesis, causes necrosis, leaf drop, the growth is altered, the chlorophyll content wills decrease, harmful mutation of plants, and animals, reduce the productivity of the crops, decrease in the number of phytoplankton and zooplankton, and harms fishes and other aquatic life. Sanjaychauwal.wordpress.com

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3. Acid Rain It is the process of deposition of acid gases from the atmosphere on land in the form of precipitation or rain. It thus increases H ions concentration of precipitation. In water whole the cocktail rain with H2SO4 and HNO3 is called acid rain. Causes of Acid Rain Oxides of sulphur and nitrogen are the major air pollutants produced by the combustion of fossils fuels from power generation, industries, factories and automobiles. Effects of Acid Rain Acid rain acidifies the soil Affects flora and fauna Affect human health Acidifies lakes and streams Affect aquatic animals and vegetation Reduces plant productivity Acid rain destroys forest Kills useful bacteria and blue green algae In Sweden more than ten thousand lakes are acidic and in USA thousands of lakes are acidic and in Germany 8% forest was cleared by acid rain. Control  Air pollution should be controlled  A forestation should be dome  Gases coming out of automobiles should be treated first before discharging out  Alternative sources of energy should be used  Catalyst process catalyst converter should be used to change toxic gases Pond Ecosystem The pond is a small body of standing water and the pond ecosystem is complex interactions between its biotic and abiotic components. Abiotic component of pond ecosystem are: Environmental factors: light, temperature, water The edaphic factors: Soil Inorganic Components are: O2, CO2, N2, nitrates, phosphates, carbonates etc. Organic components are: carbohydrates, proteins, amino acids, fats, nucleic acids Biotic components are: Producers The producers are the aquatic green plants, which may be divided into two groups. Sanjaychauwal.wordpress.com

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Microphytes (phytoplanktons) They are microscopic autotrophs, which fix solar energy. eg. Spirogyra, Zygnema, Volvox, Oedogonium. Macrophytes They are large plants, which manufacture complex food. They are of following types Submerged plants: those, which are submerged in water, are submerged plants eg Hydrilla and Utricularia Floating plants: those, which float freely in water surface, are called floating plants eg. Pistia, Nymphea and Azolla Immerged plants: those, which are rooted but emergent, are called immerged plants eg Ranunculus, Sagittaria and Typha Consumers The consumers are those heterotrophic organisms, which consume producers as food. They are also following types Primary consumers: These herbivorous animals depend upon autotrophic organisms such as microscopic plant eaters or zooplanktons, Mollusks, Beetles, Cyclops, and Daphnia etc. Secondary consumers: These are primary carnivores, which depend upon herbivorous animals for food eg. Insects, fishes, frogs, crab etc. Tertiary consumers: These are second grade of carnivores. They feed upon plants or animals (secondary consumer) therefore are called omnivores. for eg. Large fishes and frogs. Top consumers: These are third grade of carnivores, which feed upon primary, secondary, and tertiary consumers eg. Water snake, water birds etc. Decomposers These include heterotrophic microorganisms such as bacteria fungi, which break down the organic complex food from dead producers and consumers into simple inorganic compounds made available to the producers. Pond stratification: On the basis of water depth, light penetration and types of vegetation and animals there may be three zones Littoral zone: This is the shallow water region, which is usually occupied by rooted plants. This region is warmer and rich in oxygen. In this region, there is high intensity of light penetration so called epolomentic zone Limnetic Zone: this is the central part of pond upto where there is the penetration of effective light water level, oxygen content and tem[perature varies time to time in this zone. here the light penetration is lesser so called thermocline. Sanjaychauwal.wordpress.com

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Profundal Zone: This is the deep-water region where the re is no effective light penetration. There the microscopic plants and decomposers are present. So called Hypolimnion Grass Land Ecosystem ……. Community The aggregation or assembles of living organisms having mutual relationship among themselves and to their environment is called community. Assembles of plants is called plant community and the assemblage of animals is called animal community. Characters of community  Different types of species are found in the community. This is called species diversity  Some of the species are found to be dominant. This may be either due to number of individual of that species or due to the size of the body. Usually only one species is found dominant in a community. This is called species dominant.  The size of the community varies from very small to very large. The example of very small community is microorganisms found in the gut and the example of very large community is the forest community.  The community is changeable. One community can be replaced by another community in due coarse of time. This process is called succession. Succession Series of changes in a community in due course of time is called succession. This process is gradual and continuous. This process does not stop unless a stable community is formed. There are two types of succession Primary succession: The succession which starts from bare area where there was no life existed previously is called primary succession. Secondary succession: The succession which starts from bare area which had occupied by some community before is secondary succession. Causes of succession  The environmental change  The changes in nutrition, organic matters and characters of the soil cause succession. The succession due to above factor is called autogenic succession. Sanjaychauwal.wordpress.com

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 the natural disasters like flood deposition of soil erosion etc also cause

succession which is called allogenic succession Process of succession Nudation: the process of development of new species on bare areas is called nudation Invasion: the establishment of new species on bare areas is called invasion, it includes following three steps. Migration: seed, spores or propagules migrate on bare area through air water and animals. Ecesis: seed, spores or propagulaes germinate. Some of them become capable for successful growth and they get established. This process is called ecesis. Aggregation: The established species reproduce and number is increase to form large population. This process is called aggregation. Competition The large number of individuals competes for water food and space. This is called competition. The competition may be intra or inter species. They also react with the environment. Due to their activities, some modification occurs in the environment, which becomes suitable for new invaders or species, which is called reaction. Stabilization: After reaction, the community becomes more or less stable for long time, which is called climax. These different stages of the successions are called sere. Process of succession in Hydrosere The process of succession occurring in water mass like ponds, pools, and lakes is known as hydrosere In the pond, the microorganisms ie phytoplanktons (Bacteria, cyanobacteria, algae) are pioneers to be invade in the early pond water. They are consumed by zooplanktons like protozoans or smaller fishes, which after their death increase the organic content in the pond. The organic content are decomposed by decomposers like fungi, bacteria and the nutrients released. Sanjaychauwal.wordpress.com

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The released nutrients help in the growth of rooted hydrophytes like Hydrilla, Chara etc. and the submerged animals. Their dead bodies are also decomposed by microbes to release nutrients. In due course, of time water depth of pond reduced and at the margin rooted floating plants like Nympaea, Nelumbo and animals like insects larvae grow. Gradually the pond depth further decreases and concentration of nutrients increases which develop freely floating plants like Azolla Salvinia etc. Gradually dead bodies also increase. The pond becomes swampy and the rooted plants like Typha, Rumex are developed. If the water level further decrease the growth of amphibious species is unfavorable and they are replace by plant like Juncus, Cyperus of graminae family. These plants are again replaced by mesic communities As the soil become further drier then soil favors the growth of trees like Alnus and the woodland community appears. Finally, tree community is replaced by forest, which is the climax stage. Biogeochemical Cycle The elements which are required for the proper growth and development of living organisms enter into the composition of living organisms circulate more or less in cyclic manner from abiotic environment to living organisms and again back to the non living environment is called biogeochemical cycle The flow involves not only living organisms but also a series of chemical reactions in the abiotic environment these cycles are called biogeochemical cycle. Nitrogen Cycle Nitrogen is essential constituent of many biologically significant molecules such as amino acids, proteins, enzymes chlorophylls, and nucleic acids etc. The main source of nitrogen is atmosphere where it is 78%. Green plants contain nitrogen from soil solution in the form of ammonium, nitrate, and nitrite ions and the main source of all these nitrogen compounds is the atmospheric nitrogen. Nitrogen cycle consists of following steps Nitrogen fixation Conservation of free atmospheric nitrogen into the biologically acceptable form or nitrogenous compounds is known as nitrogen fixation. It is of two types Sanjaychauwal.wordpress.com

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Non-biological nitrogen fixation is the process in which lightning or electrical discharges in the clouds and produce different nitrogen oxides. These nitrogen oxides dissolve in rainwater and mix with earth surface. Certain free-living bacteria in the soil and symbiotic bacteria present in the root nodules of leguminous carry out biological nitrogen fixation and cyanobacteria present in the soil. The free-living bacteria present in the soil are like Coccus fix atmospheric nitrogen. The bacteria, which are found in the root nodules of leguminous plants, are called symbiotic bacteria they also fix atmospheric nitrogen and supply to the host plant. Different types of cayanobacteria like Nostoc, Anabaena, Spiriluna are also present in the soil which contain certain nitrogen fixing cells in the filament like heterocyst. Nitrogen assimilation The fixed nitrogen is utilized by green plants and stored in the plants in the form of protein. When plants are eaten by animals the protein is transfer to animal. This is called nitrogen assimilation. Amonification The dead bodies of plants and animals containing nitrogenous substances are acted upon a number of microorganisms like bacteria (Bacillus, Ramosus) and fungi. They utilize organic compounds and release ammonia in the soil. This process is called ammonification. Nitrification Some bacteria like Nitrosomonas converts ammonia into nitrites and the nitrites are converted into nitrates by Nitrobacter. These bacteria are called nitrifying bacteria and the conversion of ammonia into nitrate is called nitrification. Denitrification The process of conversion of nitrates into free nitrogen by certain bacteria like Bacillus denitrificans is known as denitrification. But sometime aminoacid is formed from ammonia and nitrates which is used by green plants. Carbon Cycle

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The main source of carbon is atmospheric carbondioxide. In the atmosphere the carbondioxide is 0.03%. The atmospheric carbondioxide is fixed by green plants during photosynthesis. The plants in presence of water and carbondioxide manufacture food. The carbon is then stored in different form of carbohydrates in plant body. When the plants are consumed by animals the food material is transferred to animals and they get carbon compounds and store in their body. During respiration, both plants and animals release carbondioxide into the atmosphere. Respiration takes place to produce energy where oxygen is used to breakdown the food materials. Carbondioxide is the waste product produced during the process. The CO2 is also produced in atmosphere from burning plants, animals and different other residues. It is mixed into the atmosphere during burning coal, firewood and fuel as well. After death of animals and plants, the CO2 is produced and mixed into atmosphere during fermentation. Fossilization takes place in dead plants and animals to form carbon compounds like coal and fuel as petrol or diesel. Some amount of carbondioxide is also mixed during volcanic eruption and during mineralization of rocks. See and Draw necessary Figures

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