Tag: plants and animal hormones

Quizzes (14) Questions (183)

Questions Related to plants and animal hormones

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

Which of the following do not play any role in calcium balance in the human body?

  1. Vitamin D

  2. Parathyroid hormone

  3. Thyrocalcitonin

  4. Thymosin
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Thymosin is a hormone released by the thymus. It has a major role in the maturation of the T lymphocytes. It has no role in maintaining the calcium balance in the body.
Thus, the correct answer is 'Thymosin.'
Multiple choice zoology plants and animal hormones thymus thymus gland pineal gland and thymus

Which gland atrophies in adults?

  1. Pancreas gland

  2. Thymus gland

  3. Adrenal gland

  4. Thyroid gland
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Thymus gland is a prominent gland at birth but gradually atrophies in the adult. It is a soft, pinkish, bilobed mass of lymphoid tissue. It secretes a hormone thymosin which is involved in producing immunity.

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

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

  1. Bone marrow

  2. Thymus

  3. Spleen

  4. Peyer's patches
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.

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

Central tolerance takes place in

  1. Lymph nodes

  2. Thymus

  3. Spleen

  4. Liver
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.

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

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

  1. Have passed through the thymus

  2. Synthesize and liberate antibodies

  3. Have antibody-mediated immunity

  4. Have specific receptors
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.

Multiple choice biology plants and animal hormones parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

The blood calcium level falls too low because

  1. The thyroid gland releases calcitonin, which binds to bone cells

  2. The parathyroid glands release PTH, which binds to kidney cells

  3. The thyroid gland releases thyroid hormone, which binds to small intestine cells

  4. The pancreas releases glucagon, which binds to liver cells

  5. The pituitary gland releases growth hormone, which binds to bone cells
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Parathormone of parathyroid gland increases the blood calcium level by binding to receptors present on DCT of the nephron to stimulate conditional reabsorption of calcium. Thyroid hormone does not have any specific target cell and stimulate metabolic rate by all cells. Glucagon regulates blood glucose level while growth hormone stimulate overall growth and development. Calcitonin hormone stimulates a temporary reduction in number and activity of osteoclasts (bone cells) and thereby reducing the blood calcium level. Thus, the correct answer is option A.

Multiple choice biology plants and animal hormones parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

Parathyroid maintains the calcium level in the blood by action on which of the following organs?

  1. Bone

  2. Kidney

  3. Intestine

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Parathyroid hormone regulates calcium levels in the blood, largely by increasing the levels when they are too low. 
  • It does this through its actions on the kidneys, bones and intestine. 
  • Bone parathyroid hormone stimulates the release of calcium from large calcium stores in the bones into the bloodstream. Hence, Parathyroid maintains the calcium level in the blood by action on Bone, Kidney and Intestine.
    • So, the correct answer is 'All of the above'.
Multiple choice biology plants and animal hormones parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

Parathormone influences calcium absorption in small intestine by regulating metabolism of 

  1. Vitamin C

  2. Vitamin D

  3. Vitamin B

  4. Enterogastrone
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Parathormone is secreted from the parathyroid hormone and increases blood calcium level by increasing the reabsorption of calcium from the bones. Parathormone increases calcium absorption in small intestine by regulating metabolism of vitamin D because it stimulates osteoclasts. These are the cells that cause breakdown by dissolution of calcium from bone and thus, concentration of calcium is increased in blood.
So, the correct answer is 'Vitamin D'.