Category: Biology Second Paper

Metabolically active cell growth phase is called pause-1 phase. This state is called antiphase. A cell that will no longer divide remains locked in the G1 subphase for a week or a year or forever. The characteristics of Birama-1 dasha are-
(i) Cell cycle starts in this state.
(ii) Whether a cell will participate in division depends on this stage.
(iii) Cyclin proteins, gabular proteins, fibrous proteins and RNA are produced in this subphase.
(iv) Cyclin protein binds to CDK and accelerates and regulates the process. CDK regulates the phosphorylation process.
(v) Enzymes are produced to make DNA and proteins.
(vi) Cytoplasm and nucleus of the cell increases in size.
(vii) Synthesis of various nucleotides and amino acids takes place.
(viii) In this state, the cells double in number.
(ix) Sub-phase takes 30-40% time.

(i) CDK (Cyclin Dependent Kinase) compounds provide external stimulation in interphase state.

(ii) Various hormones and growth factors provide internal stimulation during interphase.

(iii) Various metabolic activities continue in the cell during this stage. As the nucleus increases in size and many reactions take place, it is called metabolic nucleus.

(iv) DNA, RNA and protein synthesis takes place in this stage. Hence it is called synthesis stage.

(v) Chromosomes are arranged as chromatin.

(vi) In this state, the cells have the necessary energy reserves.

(vii) Increase in cell volume is greatest in this condition.

(viii) Duplication of the DNA of the cell takes place, i.e. the monad turns into a dyad.

(ix) Centrosomes of animal cells divide.

(x) This phase takes 90-95% time.

The period between two consecutive cell divisions is called interphase. This state is called rest state. The nucleus in this state is called the metabolic nucleus.

It takes 10 minutes to 24 hours for the cell cycle to complete. The cell cycle of the human body is completed in 20-24 hours. In yeast cells it takes 90 minutes. Broad bean takes 18-19 hours.

1. It takes a certain amount of time for the cell cycle to complete. The period of the cell cycle is called the natal period.
2. The cell cycle is controlled by a genetic program.
3. The cyclin-cdk complex provides intrinsic stimulation of the cell cycle.
4. Hormones and growth factors provide extrinsic stimulation of the cell cycle.
5. When cut in any part of the body, the growth factor is produced. Stimulation of this growth factor causes the surrounding cells to divide and repair the wound.
6. White blood cells make growth factors for the body’s immune system.
7. Erythropoietin is produced in the kidneys. Erythropoietin helps the bone marrow produce red blood cells.
8. The P53 protein stops the cell cycle when the cell’s DNA is severely damaged.
9. P53 protein causes cell death by apoptosis process when cell DNA is severely damaged.
10. Abnormal or uncontrolled cell cycle disrupts the growth and development of the organism. Can even cause cancer.

Interphase stage and division stage of the cell are together called cell cycle. The cycle through which cells form, grow and divide is called the cell cycle. According to scientist Lewin, the period between two periodic cell divisions is called cell cycle. According to scientist Karp, the periodic stages between the formation of two cells from one cell through cell division are called cell cycles. Growth factors (growth hormones) bind to receptor proteins on the surface of target cells (cells that will divide) to initiate the cell cycle. In 1953 scientists Howard & Pelc introduced the cell cycle. In 2001, American scientist Leland H. Hartwell discovered the master regulator of the cell cycle.

1. Structural Structure: Cells are the main structural elements of living organisms. Parenchyma, collenchyma and scherenchyma form the structure of plants.
2. Energy production: Green plants convert solar energy into chemical energy in the process of photosynthesis. Animals convert static energy into kinetic energy.
3. Balance: Different cells of the body maintain biochemical and physiological balance.
4. Transport: The transport tissues of organisms are blood, xylem and phloem. These tissues transport food, water, enzymes, hormones, mineral salts etc.
5. Metabolism: Metabolism and metabolism are together. Cells synthesize and break down a variety of chemicals in the body.
6. Digestion and absorption: Different cells of the digestive system digest and absorb food.
7. Defense: White blood cells and other cells eat germs and produce antibodies. Antibodies are active against germs.
8. Activity: Different types of activities take place in cells. This activity keeps the organism active and alive.
9. Vision: Rod cells and cone cells in the eyes of vertebrates help in vision.
10. Conduction of impulses: Muscle cells and nerve cells conduct electrical impulses in the body.
11. Connection: Blood cells and bone marrow maintain the connection between different cells and tissues of the body.
12. Secretion: Hormones, enzymes and honey are secreted from different types of glands.
13. Excretion: Nitrogenous waste products are produced as a result of metabolism in the body. These waste products are excreted through the kidneys.
14. Reproduction: Somatic cells carry out asexual reproduction and reproductive cells carry out sexual reproduction.

The by-products produced in the metabolism of protoplasm are called waste products. These waste materials accumulate in leaves, fruit bark, stem bark, mother cells and tissues. Different types of waste materials are-

(i) Resin: The resinous substance present in the resin ducts of plants like pine, Arocaria etc. is called resin. Resin is used to smooth the strings of sitar and violin.

(ii) Tannin: Tannins are present in the fruit and seeds of tamarind and gab plants. Tannins are used to tan leather, make dyes and inks.

(iii) Gum : Plants like Jiga, Sajina, Acacia etc. contain gum or gum. It is used as glue.

(iv) Organic Acids: Malic acid in cherry and tomato, citric acid in pineapple, grape and lemon, oxalic acid in amrule, tartaric acid in tamarind, date and grape, glycolic acid in beet and raw grapes, lactic acid in opium and cucumber, tannic acid in tea. , olive oil contains oleic acid and apricot contains ascorbic acid.

(v) Latex : Stems, leaves, flowers and fruits of plants like banyan, fig, ash^thth, akanda, karbi, akanda, safeda, jackfruit etc. contain tarukshir or latex.

(vi) Terpenoids: Tulsi leaves, mint leaves, Pinus cells etc. contain terpenoids.

(vii) Alkaloids : Nicotine in tobacco, daturine in dhutura, caffeine in coffee, opium in opium, serpentine in sarpagandha, quinine in cinchona etc.

(viii) Volatile oil: Flowers, fruits and leaves of plants like lemon, tulsi, kamini, raktadrona, svetadrona, eucalyptus etc. contain volatile oil.

(ix) Mineral crystals: Mineral crystals are of two types. Cystoliths and raphides. Grapefruit-like calcium carbonate is called a cystolith. Cystoliths are present in the leaves of plants like banyan, ash, fig, rubber etc. Needle-like calcium oxalate is called raphide. Plants like Manakchu, Olakchu, Mukhikchu etc. have raphides on their stems and leaves.

Mineral crystals are of two types. Cystoliths and raphides. Grapefruit-like calcium carbonate is called a cystolith. Cystoliths are present in the leaves of plants like banyan, ash, fig, rubber etc. Needle-like calcium oxalate is called raphide. Plants like Manakchu, Olakchu, Mukhikchu etc. have raphides on their stems and leaves.