Tag: biology

Questions Related to biology

Number of cells daily replaced in human body is

mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

  1. $1 \times 10^9$

  2. $5 \times 10^9$

  3. $1 \times 10^{10}$

  4. $5 \times 10^{10}$

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Correct Option: A

Heparin is formed by.

mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

  1. Liver cells

  2. Plasma cells

  3. Blood cells

  4. Spleen cells

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Correct Option: A
Explanation:
Heparin is a naturally occuring anticoagulant which is synthesised in Liver as well as blood cells such as basophils and mast cells. Heparin prevents the formation of blood clots and extension of existing blood clots within the blood.
So, the correct answer is 'Both A and C'.

Fat absorbed from gut is transported in blood as

mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

  1. Micelles

  2. Liposomes

  3. Chemomicrons

  4. Chylomicrons

  5. Phagocytes

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Correct Option: D
Explanation:
The products of lipid digestion enter the body by a different process and a different route. These products namely, long chain fatty acids, monoglycerides and diglycerides are insoluble in water and cannot be directly absorbed from intestinal contents. They combine with the bile salts and phospholipids to form small spherical water-soluble molecular aggregates called micelles. From the micelles, fatty acids, glycerides and fat-soluble vitamins are actively absorbed into the intestinal cells. In these cells, the bile salts are freed and fatty acids, glycerol, monoglycerides and diglycerides are resynthesized into fats. The fats are then mixed with cholesterol and coated with special proteins forming small globules called chylomicrons The latter are transported by exocytosis out of the epithelial cells into a lacteal.
Thus, the correct answer is option D. 

Basement membrane is formed of.

mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

  1. Epidermal cells

  2. Endodermal cells

  3. Both A and B

  4. None of the above but present below epithelial cells

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Correct Option: D
Explanation:

All epithelia are separated from their underlying tissues by an extracellular basement membrane which is fibrous in nature. The basement membrane is the fusion of two lamina namely, the basal lamina and the reticular lamina. The lamina reticularis is attached to the basal lamina with collagen anchoring fibrils and fibrillin microfibrils. The two layers together are collectively referred to as the basement membrane.

So D is the correct option. 

Angiotensinogen is a protein secreted by

mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

  1. Juxtaglomerular cells

  2. Macula densa cells

  3. Endothelial cells

  4. Liver cells

Show answer
Correct Option: D
Explanation:
Angiotensinogen is a plasma protein produced and secreted by liver cells. It is a sole precursor of all angiotensin peptide. Juxtaglomerular cells secrete renin which acts on angiotensinogen to release angiotensin I and then it is converted to angiotensin II by the action of enzyme angiotensin-converting enzymes.
So, the correct answer is 'Liver cells'.

Calcium occurs in

mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

  1. All body cells

  2. Bones and teeth

  3. Cells of respiratory system

  4. 3% of mineral content

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Correct Option: A

Division of the nucleus is called ..........

mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

  1. Cytokinesis

  2. Karyokinesis

  3. Replication

  4. None of the above

Show answer
Correct Option: B
Explanation:

Division of the nucleus is called karyokinesis. The process of partition of a cell's nucleus into the daughter cells during cell division is called karyokinesis. All the changes in a nucleus that occur during cell division are collectively termed as karyokinesis. It has four stages prophase, metaphase, anaphase, and telophase.

So the correct answer is "Karyokinesis".

All nuclear changes that occur during mitotic cell division are collectively called as

mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

  1. Karyokinesis

  2. Cytokinesis

  3. Recombination

  4. Both A and B

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Correct Option: A
Explanation:

All nuclear changes (Prophase, metaphase, anaphase, and telophase) that occurs during mitotic cell division are collectively called as karyokinesis. Mitotic cell division consists of two steps. The first step is karyokinesis where nuclear division takes place which is followed by cytokinesis i.e the division of cytoplasm takes place and individual daughter cells are formed. So, the correct answer is 'Karyokinesis'.

The epithelial cells lining the stomach of vertebrates are protected from damage by HCl because.

mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

  1. HCl is too dilute

  2. The epithelial cells are resistant to the action of HCl

  3. HCl is neutralized in the stomach

  4. The epithelial cells are covered by mucus

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Correct Option: D
Explanation:
The epithelial cells lining the stomach of vertebrates are protected from damage by HCl because 'the epithelial cells are covered by a mucous secretion'.
So the correct option is D.

Epithelial cells serves the function of protection, secretion and absorption and is separated from the other tissues below by a _____.

mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

  1. Basal lamina

  2. Lamina propria

  3. Connective tissue

  4. Stratum granulosum

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Correct Option: B