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

The correct option is A There are three main types cytotoxic T - cells, helper T - cells and suppressor T - cells

Of the given options, the correct statement is "There are three main types cytotoxic T - cells, helper T - cells and suppressor T - cells".
A T cell, or T lymphocyte, is a type of lymphocyte (a subtype of white blood cell) that plays a central role in cell-mediated immunity. The T- lymphocytes are so called because although they originate in the bone marrow, they mature in the thymus.
There are three main types, namely, cytotoxic T - cells, helper T - cells and suppressor T - cells.
T cells are involved in cell-mediated immunity, that is they recognise and kill infected cells directly