Tag: biology

Questions Related to biology

What will happen if platelets were absent in the blood?

  1. The process of clotting will be affected.

  2. Kwashiorkor will be the result.

  3. RBC will be ruptured.

  4. The blood will become more liquid.


Correct Option: A
Explanation:

Platelets are the colourless cell fragments present in the blood. They are involved in the clotting. In the absence of platelets, the process of clotting will be affected. If there will be any wound when platelets are absent, the animal will die by shredding of all the blood.

Therefore, the correct answer is option A.

One of the common symptoms observed in people infected with dengue fever is

  1. Significant decrease in RBC count

  2. Significant decrease in WBC count

  3. Significant decrease in platelets count

  4. Significant increase in platelets count


Correct Option: C
Explanation:
Dengue is a type of fever caused by the dengue virus and propagated by mosquitoes. A significant decrease in the number of platelets is observed in this disease.
Thus, the correct answer 'Significant decrease in platelets count.'

Identity the wrongly matched pairs 

  1. Monocyte - Actively phagocytic

  2. Thrombocyte - Produces antibodies

  3. Lymphocyte - Initiates blood clotting

  4. Eosinophil - Associated with allergy


Correct Option: B
Explanation:

Monocytes are actively phagocytic and they take in the invading pathogen or cell through the method of phagocytosis.

thrombocytes are also known as platelet and the main function is in blood clotting. They do not produce any antibodies.
Lymphocytes have to play an important role in the immune system as well as blood clotting. 
Eosinophil cells are also responsible for immunity and are associated with allergic reactions in the body caused due to allergents as well as some infections.
So the correct answer is ' Thrombocyte- Produces antibodies'.

Platelets are formed by .....P ..... of special cells in ....Q.......

  1. P - Division , Q - Bone Marrow

  2. P - Division , Q - Lymph nodes

  3. P - Fragmentation , Q - Bone Marrow

  4. P - Fragmentation , Q - Lymph nodes


Correct Option: C
Explanation:

Platelets are formed by the fragmentation of special cells named megakaryocytes in bone marrow cell so answer is option.        

 C. P- FRAGMENTATION , Q - Bone marrow

Megakaryocyte forms

  1. Leucocytes

  2. Erythrocytes

  3. Monocytes

  4. Thrombocytes


Correct Option: D
Explanation:

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

Critical count of platelet is

  1. 40, 000 / mm$^3$

  2. 1 lac / mm$^3$

  3. 2 lac / mm$^3$

  4. 4 lac / mm$^3$


Correct Option: A
Explanation:

Critical count of platelet is 40, 000 / mm$^{3}$. 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. The normal number of platelets in the blood is 150,000 - 400,000 platelets per microliter (mcL). A low platelet count is below 150,000. If the platelet count is below 50,000, the risk of bleeding is very high. So, it is called critical platelet count.

Life span of blood platelets in mammals is about

  1. 3 days

  2. 8 days

  3. 1 month

  4. 20 days


Correct Option: B
Explanation:
Platelets are the smallest of the three major types of blood cells. Platelets are anuclear cytoplasmic fragments essential for blood clotting and wound healing. Blood platelets begin their lives as hematocytoblasts, or stem cells. Blood platelets have a life span of 8-10 days, at the end of which they undergo programmed cell death or apoptosis.
Hence, answer is '8 days'.

Which of the following results from cell fragmentation?

  1. RBC

  2. WBC

  3. Plasma

  4. Platelets


Correct Option: D
Explanation:

Platelets are the cells found in blood which helps in the clotting of the blood. The formation of platelets takes place in bone marrow from large bone marrow cells known as megakaryocytes. These cells after becoming mature enough, undergo the process of cell fragmentation to produce platelet cells. The hormone that help in platelet production is thrombopoietin. 

So, the correct answer is D.

Low platelet count results in

  1. Low bleeding

  2. Excessive bleeding

  3. Growth

  4. Both B and C


Correct Option: B
Explanation:

Platelets are the parts of the blood that help the blood clot. They are smaller than red or white blood cells. If the number of platelets is too low, excessive bleeding can occur. However, if the number of platelets is too high, blood clots can form thrombosis, which may obstruct blood vessels and result in such events as a stroke. 

Therefore, the correct answer is option B.

With reference to the blood in a normal person, which one of the following statements is correct?

  1. Compared to arteries, veins are less numerous and hold less of the body's blood at any given time.

  2. Blood cells constitute about 70 percent of the total volume of the blood.

  3. White blood cells (WBC) are made by lymph nodes only.

  4. The blood has more platelets than WBC.


Correct Option: D
Explanation:
Blood is a specialized body fluid. It has four main components: plasma, red blood cells, white blood cells and platelets. The blood has more platelets than WBC. A normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. An average normal range for white blood cells is between 4,500 and 10,000 /mcl.
Blood has many different functions. They are as follows:
  • Transporting oxygen and nutrients to the lungs and tissues.
  • Forming blood clots to prevent excess blood loss.
  • Carrying cells and antibodies that fight infection.
  • Bringing waste products to the kidneys and liver, which filter and clean the blood.
  • Regulating body temperature.