Question

What is true about T-lymphocytes in mammals:

• A. There are three main types-cytotoxic T-cells, helper T-cells and suppressor T-cells
• B. These originate in lymphoid tissues
• C. They scavenge damaged cells and cellular debris
• D. These are produced in thyroid

Answer 1

Answer: (A)

There are three main types-cytotoxic T-cells, helper T-cells and suppressor T-cells

Answer 2

T-lymphocytes, or T-cells, play a critical role in the immune system. Among T-cells, there are indeed three main types:

1. Cytotoxic T-cells (also known as killer T-cells) that are responsible for destroying infected or abnormal cells.
2. Helper T-cells that coordinate immune responses and activate other immune cells.
3. Suppressor T-cells (also known as regulatory T-cells) that help regulate and suppress excessive immune responses to prevent autoimmune reactions.

The other statements are not accurate:
- T-lymphocytes originate in the bone marrow, not lymphoid - tissues.
- They are involved in immune responses but do not scavenge damaged cells or cellular debris.
- They are not produced in the thyroid.

So, the correct option is (A): There are three main types-cytotoxic T-cells,helper T-cells and suppressor T-cells