Tag: biology

Questions Related to biology

Blood platelets occur in the blood of ____________.

biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

  1. Birds

  2. Mammals

  3. Reptiles

  4. Amphibians

Show answer
Correct Option: B
Explanation:

Only mammals have platelets, tiny cells without nuclei that are responsible for plugging the leaks in the blood vessels. Other animals use more conventional systems of hemostasis. Some marine invertebrates have a single type of blood cell, responsible for hemostasis, but also for other types of defences. Non-mammalian vertebrates have specialized nucleated thrombocytes to do the job.


So, the correct answer is 'Mammals'.

Blood platelets are.

biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

  1. Nucleated cells

  2. Non-nucleated cells

  3. Non-nucleated cell fragments

  4. Nucleated cell fragments

Show answer
Correct Option: C
Explanation:

Platelets are small, non-nucleated cells that are derived from megakaryocytes in the bone marrow. Platelets circulate in the blood, sense damage to a blood vessel and accumulate at these sites, where they initiate blood clotting. They are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow.


So, the correct answer is 'Non-nucleated cell fragments'.

Instead of platelets, the non-mammals possess clotting factor in.

biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

  1. Nucleated cells called thrombocytes

  2. RBC

  3. WBC

  4. Plasma

Show answer
Correct Option: A
Explanation:

Only mammals have Platelets. Non-mammals possess thrombocytes which are nucleated cells which have been shown to have a haemostatic function paralleling that of mammalian platelets.


So, the correct answer is 'Nucleated cells called thrombocytes'.

Megakaryocytes.

biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

  1. Produce leucocytes

  2. Form blood platelets

  3. Are called bone cells

  4. Are carriers of oxygen

Show answer
Correct Option: B
Explanation:

A megakaryocyte is a large bone marrow cell with a lobated nucleus responsible for the production of blood thrombocytes (platelets), which are necessary for normal blood clotting.


So, the correct answer is 'Form blood platelets'.

The life span of thrombocytes is

biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

  1. 4 to 5 weeks

  2. 3 to 4 weeks

  3. 3 to 7 days

  4. None of these

Show answer
Correct Option: C
Explanation:
The average life span of circulating platelets is 8 to 9 days. Life span of individual 3 to 7 days thrombocytes is controlled by the internal apoptotic regulating pathway, which has a Bcl-xL timer. Old thrombocytes are destroyed by phagocytosis in the spleen and liver. So, the correct answer is "3 to 7 days.'

$1$ li. of oxygenated blood can deliver how much amount of $O _2$ to the tissue under normal conditions.

biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

  1. $4$ ml

  2. $50$ ml

  3. $20$ ml

  4. $159$ ml

Show answer
Correct Option: A

Ornithine cycle helps to remove _______ from blood.

biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

  1. Urea

  2. $NH _3$

  3. Uric acid

  4. Arginine

Show answer
Correct Option: A

What is the life span of thrombocytes?

biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

  1. 7 - 10 days

  2. 3 - 4 weeks

  3. 2 - 5 weeks

  4. None of the above

Show answer
Correct Option: A
Explanation:

Platelets, also called thrombocytes, are blood cells whose function is to stop bleeding. The average life span of circulating platelets is 7 to 10 days.

Smallest blood cells are

biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

  1. RBC

  2. WBC

  3. Platelets

  4. None of the above

Show answer
Correct Option: C
Explanation:

Platelets, also called thrombocytes, are blood cells whose function is to stop bleeding. Platelets have no nucleus: they are fragments of cytoplasm, which are derived from the megakaryocytes of the bone marrow, and then enter the circulation. These unactivated platelets are biconvex discoid structures. They are smallest of the three major blood types. They make up a tiny portion of the blood volume.

Life span of platelet is

biology blood circulatory system of human blood clotting platelets and their function defence against infectious disease

  1. 8 - 9 days

  2. 9 - 12 days

  3. 20 - 30 days

  4. 90 days

Show answer
Correct Option: A
Explanation:

Life span of platelets is 8 - 9 days. Platelets, also called thrombocytes, are blood cells, whose function is to stop bleeding. Platelets have no nucleus: they are fragments of cytoplasm, which are derived from the megakaryocytes of the bone marrow, and then enter the circulation. These unactivated platelets are biconvex discoid structures. Life span of individual platelets is controlled by the internal apoptotic regulating pathway. Old platelets are destroyed by phagocytosis in the spleen and liver.