Tag: endocrine system in humans

Questions Related to endocrine system in humans

Insulin receptors are.

zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

  1. Extrinsic proteins

  2. Intrinsic proteins

  3. G-proteins

  4. Trimeric proteins

Show answer
Correct Option: A
Explanation:
Insulin receptors are extrinsic proteins. They are made up of an alpha and a beta subunit that are held together by disulphide bonds. Insulin, which is a polypeptide hormone, binds to the extracellular face of the α-subunits.
Thus, the correct answer is 'Extrinsic proteins.'

Which of these is a second messenger?

zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

  1. ATP

  2. cAMP

  3. GTP

  4. ATP and AMP

Show answer
Correct Option: B
Explanation:
Second messengers are the intracellular molecules released by the cell in response to exposure to extracellular molecules i.e. first messengers. Extracellular molecules trigger the release of the secondary messengers.
  • The cAMP is a derivative of the ATP. It is used for many intracellular signalling pathways.
  • ATP is a nucleotide. It is created during respiration in the mitochondria of eukaryotic cells.
  • AMP is nucleoside triphosphate i.e. a type of nucleotide. AMP is used as a monomer of RNA, also used to generate ATP.
  • GMP is a nucleotide, that is used as a monomer of RNA
So, the correct answer is 'cAMP' 

A hormone that stimulates an endocrine gland to grow and secrete its hormone is known as

zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

  1. Endocrine hormone

  2. Tropic hormones

  3. Exocrine hormone

  4. None of these

Show answer
Correct Option: B
Explanation:

  • A tropic hormone is a hormone that stimulates an endocrine gland to grow and secrete its hormones. (One hormone causes another hormone to do something) 
  • In humans, tropic hormones are secreted by the adenohypophysis(anterior pituitary gland). Hence, A hormone that stimulates an endocrine gland to grow and secrete its hormone is known as Tropic hormones
So, the correct answer is 'Tropic hormones'.

Receptors are :

zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

  1. Proteins

  2. Lipids

  3. Carbohydrates

  4. Nucleic acids

Show answer
Correct Option: A
Explanation:

Receptor is a molecule usually found on the surface of a cell, that receives chemical signals from outside the cell. When such external substances bind to a receptor, they direct the cell to do something, such as divide, die, or allow specific substances to enter or exit the cell.

Receptors are proteins embedded in either the cell's plasma membrane (cell surface receptors), in the cytoplasm, or in the cell's nucleus (nuclear receptors), to which specific signaling molecules may attach.

Which of the following helps in formation of alveoli of the mammary glands?

zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

  1. Estrogen

  2. Prolactin

  3. Progesterone

  4. All of the above

Show answer
Correct Option: D
Explanation:

  • In both males and females have glandular tissue within the breasts however, in females the glandular tissue begins to develop after puberty in response to estrogen release. 
  • Mammary glands only produce milk after childbirth. During pregnancy, the hormones progesterone and prolactin are released. Hence, Estrogen, Prolactin and Progesterone help in the formation of alveoli of the mammary glands.
So, the correct answer is 'All of the above'.

Hormone that functions through secondary messenger is

zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

  1. Glucagon

  2. Estrogen

  3. Cortisol

  4. Iodothyronines

Show answer
Correct Option: A

How many of the given hormones act on the target cells by binding to intracellular receptors?
a. Iodothyronines 

b. Somatostatin 
c. Estradiol 
d. Cortisol 
e. Oxytocin 
f. Aldosterone 

zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

  1. Two

  2. Three

  3. Four

  4. Five

Show answer
Correct Option: C
Explanation:
  • Hormones that act on the target cells by binding to intracellular receptors are steroids. 
a. Iodothyronines - thyroid hormones
b. Somatostatin - polypeptide hormone
c. Estradiol - steroid hormone
d. Cortisol - steroid hormone
e. Oxytocin - steroid hormone
f. Aldosterone - steroid hormone

So, the correct option is C.

Which of the following helps in differentiation of lymphocytes?

zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

  1. Cytosin

  2. Thymosin

  3. Cyclin

  4. None of the above

Show answer
Correct Option: B
Explanation:

  • Thymosin hormones are typically produced by the thymus gland and trigger the creation of T-cells, which are used by the immune system to fight disease. 
  • Once puberty occurs in a human, a normal thymus has created the T-cells needed by the body and begins to shrink, eventually being replaced by fatty tissue. Hence, Thymosin helps in the differentiation of lymphocytes.
So, the correct answer is 'Thymosin'.

The LH surge is essentially a signal sent from the brain to the ovary,which indicates

zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

  1. Onset of implantation

  2. An egg is mature

  3. Fertilization

  4. None of the above

Show answer
Correct Option: B
Explanation:

  • The LH surge causes the initiation of the process of ovulation. 
  • After ovulation, the follicle is transformed into the corpus luteum, which is stimulated by LH.
  •  It occurs roughly 36 hours before ovulation which indicates egg has matured and is ready for fertilisation. Hence, The LH surge is essentially a signal sent from the brain to the ovary, which indicates An egg is mature.
So, the correct answer is 'An egg is mature'.

Which hormone is antagonistic to calcitonin?

zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

  1. TSH

  2. Parathyroid

  3. Thyroxine

  4. None of the above

Show answer
Correct Option: B
Explanation:

  • Parathyroid hormone (PTH) is essential for the physiologic maintenance of mineral homeostasis. 
  • PTH regulates the mineral transport in bone and kidney and through its secondary actions on mineral transport in the intestine. 
  • Calcitonin, in many ways, acts as a physiologic antagonist to PTH. Hence,  Parathyroid hormone is antagonistic to calcitonin
So, the correct answer is 'Parathyroid'.