Biology

Human Immunity and Blood

2,096 Questions

Human immunity and blood questions cover the physiological mechanisms protecting the body against diseases and the components of blood. Topics include blood groups, cell mediated immunity, monoclonal antibodies, and blood coagulation. These biology topics frequently appear in general science sections of competitive exams.

Blood groupsCell mediated immunityMonoclonal antibodiesBlood coagulationCancer immunology

Human Immunity and Blood Questions

Multiple choice

Blood platelets are also known as thrombocytes. Which of the following statements is correct regarding the blood platelets?

  1. They are present in greater number than RBCs.

  2. They release the main clotting factors in the blood.

  3. They attach to the walls of damaged blood vessels.

  4. They conjoin in the presence of prostacyclin.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In case of injury, the damaged endothelial cells lining the blood vessel release von Willebrand's Factor which makes the surfaces sticky. The platelets start adhering to the surfaces of endothelial cells. This effect is called platelet adhesion.

Multiple choice

In humans, the red blood cells

  1. are secreted into the circulation as immature cells known as reticulocytes

  2. have life span of about 10 days

  3. depend on mitochondria for their ATP synthesis

  4. are formed by budding off megakaryocytes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This statement is correct. Reticulocytes are young, anucleate red blood cells,  which are released from bone marrow into the blood in increased numbers as a response to anemia.

Multiple choice

Which of the following is an incorrect statement?

  1. Mature mammalian erythrocytes are enucleated.

  2. Formation of RBC's is known as Erythropoiesis.

  3. A hormone called Erythropoietin regulates the production of RBC's.

  4. RBC's arise from haemocytoblasts in the stem cells of bone marrow.

  5. The lifetime of RBC's is about 120 days.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The hormone Erythropoietin regulates the production of RBC's.

Multiple choice

Which of the following statements is incorrect?

  1. Erythrocytes are destroyed in the spleen and liver.

  2. Folic acid and vitamin B12 are essential for erythrocyte formation.

  3. Granulocytes and agranulocytes are both types of thrombocytes.

  4. Thrombocytes are essential for blood coagulation.

  5. Erythrocytes are formed in the bone marrow.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Granulocytes and agranulocytes are both types of leucocytes (WBCs).

Multiple choice

Leucopenia is the condition in which

  1. the total number of leucocytes decreases below 5000/cu mm

  2. bone marrow is destroyed

  3. leucopoiesis stops

  4. the total number of leucocytes increases above 6000/cu mm

  5. leucocytes show abnormal phagocytosis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In leucopenia, the total number of leucocytes decreases below 5000/cu mm. Lowering in the total count (TC) and differential count (DC) of WBC results into leucopenia.

Multiple choice

_______ is/are the primary organ(s) affected during tuberculosis.

  1. Bone marrow

  2. Spleen

  3. Intestine

  4. Lungs
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Tuberculosis, MTB or TB (short for Tubercle bacillus), in the past also called Phthisis pulmonalis or consumption, is a widespread, and in many cases fatal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis generally affects the lungs.