Question

The cell-mediated immunity inside the human body is carried out by:

• A. Thrombocytes
• B. T-lymphocytes
• C. Erythrocytes
• D. B-lymphocytes

Answer 1

The correct option is B

T-lymphocytes

The correct option is B:

Explanation of the correct option:

1. Acquired immunity includes cell-mediated immunity.
2. Cell mediated immune response is carried out by T-lymphocytes.​
3. It involves the destruction of infected cell or the pathogens by these T cells.
4. T-lymphocytes go through a maturation process in the thymus gland, where they become mature.
5. They, like other blood cells, begin in haematopoietic stem cells, which have their own receptors known as T-cell receptors.
6. They travel through the lymphatic system and become activated when they come into contact with infections.

Explanation of the incorrect option:

Option A:

1. Thrombocytes are disc-shaped cells that can be found in the blood and spleen.
2. These are actually fragments of megakaryocytes, which are very large cells found in the bone marrow.
3. They aid in the formation of blood clots, which serve to slow or stop bleeding and aid wound healing.

Option C:

1. Red blood cells are also known as erythrocytes (RBCs).
2. They are biconcave cells that transfer oxygen and carbon dioxide between the lungs and the rest of the body.
3. Iron-containing haemoglobin is present in these cells.

Option D:

1. Antibodies are produced up of B-lymphocytes, which are a type of cell.
2. Antibodies and other macromolecules found in extracellular fluids mediate humoral immunity.

Final answer: The cell-mediated immunity inside the human body is carried out by T-lymphocytes.