Tag: thymus gland

Questions Related to thymus gland

The regression in size of which organ is associated with reduction in the power of defence against invasion by pathogens with ageing?

zoology plants and animal hormones thymus thymus gland pineal gland and thymus

  1. Bone marrow

  2. Thymus

  3. Spleen

  4. Peyer's patches

Show answer
Correct Option: B
Explanation:

The thymus gland, located behind our sternum and between our lungs, is only active until puberty.

After puberty, the thymus starts to slowly shrink and become replaced by fat.
So, the correct option is 'Thymus'.

Central tolerance takes place in

zoology plants and animal hormones thymus thymus gland pineal gland and thymus

  1. Lymph nodes

  2. Thymus

  3. Spleen

  4. Liver

Show answer
Correct Option: B
Explanation:

Central tolerance is the tolerance established by deleting autoreactive lymphocyte clones before they develop into fully grown immunocompetent cells. It occurs primarily in the thymus.

So, the correct option is 'Thymus'.

Which one of these does not pertain to B-cells?

zoology plants and animal hormones thymus thymus gland pineal gland and thymus

  1. Have passed through the thymus

  2. Synthesize and liberate antibodies

  3. Have antibody-mediated immunity

  4. Have specific receptors

Show answer
Correct Option: A
Explanation:

B cells develop in the bone marrow but achieve maturity in peripheral lymphoid organs. Developmental stages are defined by the successful expression of heavy-chain and light-chain immunoglobulin genes. B cells provide humoral immunity against extracellular pathogens through antibody production. Antibodies neutralize pathogens and toxins, facilitate opsonization, and activate complement. The B-cell receptor or BCR is composed of immunoglobulin molecules that form a type 1 transmembrane receptor protein usually located on the outer surface of a lymphocyte type known as B cells. 


So, the correct option is 'Option A'.