Tag: biology

Questions Related to biology

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

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

  1. Bone

  2. Kidney

  3. Intestine

  4. All of the above

Show answer
Correct Option: D
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'.

Which endocrine gland becomes inactive in old age?

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

  1. Adrenal

  2. Pineal

  3. Thymus

  4. Pituitary

Show answer
Correct Option: C
Explanation:

Thymus is well developed in new born child and grows upto the age of puberty after that it starts shrinking and almost disappears in old age.

Parathormone influences calcium absorption in small intestine by regulating metabolism of 

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

  1. Vitamin C

  2. Vitamin D

  3. Vitamin B

  4. Enterogastrone

Show answer
Correct Option: B
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'.

Hormone responsible for regulation of calcium and phosphorus homeostasis is secreted by

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

  1. Pituitary

  2. Parathyroids

  3. Thymus

  4. Pancreas

Show answer
Correct Option: B
Explanation:

The parathyroid glands are small endocrine glands in the neck that produce parathyroid hormone. Humans have four parathyroid glands, which are usually located behind the thyroid gland and in rare cases, within the thyroid gland or in the chest. Parathyroid glands control the amount of calcium in the blood and within the bones.

Which of the following statements is correct for 'parathormone'?

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

  1. It increases blood calcium level and decreases calcium store of the bone

  2. It decreases blood calcium level and increased calcium store of the bone

  3. It increases blood glucose level and decreases calcium store of the bone

  4. It decreases blood glucose level and increases calcium store of the bone

Show answer
Correct Option: A

In which of the following options, hormone is not matching with its source and function?

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

  1. Hormone- Glucocorticoids, Source-Adrenal cortex, Function-Produces anti-inflammatory reactions

  2. Hormone-Vasopressin, Source-Posterior pituitary, Function-Stimulates resorption of water and electrolytes

  3. Hormone-Parathyroid hormone, Source-thyroid, Function-Decreases the blood $Ca^{2+}$ level

  4. Hormone-Melatonin, Source-Pineal gland, Function-Maintains sleep-wake cycle

Show answer
Correct Option: C
Explanation:

Hormone released by the parathyroid gland is parathyroid hormone also called parathormone or parathyrin, this hormone regulates the Ca$^{+2}$ concentration in the serum by acting upon bone, kidney and intestine.

So, the correct answer is 'Hormone-Parathyroid hormone, Source-thyroid, Function-Decreases the blood Ca$^{+2}$ level'

The blood calcium level is lowered by the deficiency of.

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

  1. Thyroxine

  2. Calcitonin

  3. Parathormone

  4. Both (a) and (b)

Show answer
Correct Option: C
Explanation:

Parathormone secreted by parathyroid gland regulates the level of calcium in the blood. It stimulates the release of calcium from the bones into the blood, increases calcium absorption from the intestine into the blood and it also increases calcium reabsorption from the nephrons into the blood. Therefore, its deficiency leads to low blood calcium level.

Parathormone influences calcium absorption in the small intestine by regulating the metabolism of 

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

  1. Vitamin C

  2. Vitamin D

  3. Vitamin ${ B } _{ 6 }$

  4. Enterogasterone

Show answer
Correct Option: B
Explanation:

The kidney processes Vitamin D into calcitriol, the active form that is most effective in assisting intestinal absorption. This process is stimulated by parathyroid hormone. Vitamin D is an important co-factor in the intestinal absorption of calcium, as it increases the number of calcium binding proteins, involved in calcium absorption through the apical membrane of enterocytes in the small intestine.

The pituitary gland by virtue of its tropic hormones controls the secretory activity of other endocrine glands. Which one of the following endocrine glands can function independent of the pituitary gland?

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

  1. Adrenals

  2. Gonads

  3. Thyroid

  4. Parathyroid

Show answer
Correct Option: D
Explanation:

Parathyroid glands are small endocrine glands in the neck of humans and other tetrapods that produce parathyroid hormone. Humans usually have four parathyroid glands, variably located on the back of the thyroid gland. Parathyroid hormone and calcitonin (one of the hormones made by the thyroid gland) have key roles in regulating the amount of calcium in the blood and within the bones. The major function of the parathyroid glands is to maintain the body's calcium and phosphate levels within a very narrow range, so that the nervous and muscular systems can function properly. The parathyroid glands do this by secreting parathyroid hormone.

So the correct option is 'parathyroid'.

Name the two hormones that regulates blood calcium levels in the body

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

  1. Insulin and glucagon

  2. Thyroxine and estrogen

  3. Thyrocalcitonin and parathyroid hormone

  4. Prolactin and oxytocin

Show answer
Correct Option: C
Explanation:

Thyrocalcitonin (TCT) is secreted when calcium level in blood is high. It then lowers the levels by suppressing  release of calcium ions from bones. Whereas parathyroid hormone increases the blood calcium level by increasing calcium absorption from intestine and mobilising calcium from bones to blood.