Biology · General Awareness

Human Endocrine System

1,530 Questions

The human endocrine system comprises glands that secrete hormones to regulate bodily functions like metabolism, growth, and reproduction. Competitive exams frequently test the specific roles of hormones such as adrenaline, insulin, and progesterone. Use these questions to master the locations and functions of different hormones.

Hormone functionsIslets of LangerhansFight or flight responseBlood pressure regulationFemale sex hormonesWater soluble hormones

Human Endocrine System Questions

Multiple choice

Follicle stimulating hormone functions in

  1. males

  2. females

  3. both males and females

  4. infants
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

FSH stimulates the process of spermatogenesis and sperm formation in males and stimulates formation of ovaries in females.

Multiple choice

Which of the following hormones is hydrophilic?

  1. Progesterone

  2. Testosterone

  3. Thyroxine

  4. Epinephrine

  5. Cortisol
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Epinephrine is a small charged water soluble hormone, which is derived from amino acids and it function as hormone and neurotransmitter.

Multiple choice

The activated stimulatory G-protein’s subunit in a cAMP signaling cascade is

  1. the G-alpha subunit

  2. the G-beta subunit

  3. the Gama subunit

  4. the Gama, beta subunit

  5. the alpha beta subunit
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option because the binding of the ligand to the receptor promotes the exchange of GDP for GTP and once the GTP binds to the G-proteins, the G-beta and Gama subunits dissociates and then G-alpha subunit becomes the activated stimulatory G-protein’s subunit.

Multiple choice

Which of the following statements is incorrect as far as G-protein mediated signal transduction is concerned?

  1. G-proteins have intrinsic GTPase activity.

  2. Activated G-protein transmits signals by binding to other proteins.

  3. G-protein exists as GDP and GTP-bound forms.

  4. The 7TM receptors are coupled to G-proteins.

  5. G-proteins are structurally and functionally similar.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is not true because different G-proteins exist. There are some thousand heteromeric G proteins as the human genome possesses in excess of 15 genes for the alpha subunits, more than 5 genes for beta subunit and nearly 10 encoding the gama subunits. For example, G-alphaS stimulates adenylate cyclase, G-alpha i inhibits adenylate cyclase. This shows that all the G-proteins are not similar.

Multiple choice

In a G protein mediated signal transduction cascade of cAMP, adenylase cyclase is activated by

  1. G-alpha GDP complex with G-beta, Gama subunits

  2. G-beta GDP Complex

  3. G-alpha-beta GDP complex

  4. G-beta-gama GDP complex

  5. G-alpha GTP complex
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

GTP in addition to the G protein is essential for the signal transduction to proceed. G-alpha is the activated subunit of G-protein. The binding of a ligand like epinephrine causes conformational change in the G-protein that assist in making the nucleotide binding site of the G-protein more accessible to the cytosol where the concentration of GTP is high. The alpha unit of it releases the GDP and binds to GTP. In other words, GTP is exchanged for the GDP. The binding of GTP causes additional conformational change in G alpha subunit and then G-protein disassociates to leave beta and Gama units. G alpha-GTP complex then binds to adenylate cyclase and activates it.

Multiple choice

Which of the following pairs is a mismatch?

  1. Pituitary : Growth hormone

  2. Thyroid : Thyroxine

  3. Parathyroid : Insulin

  4. Ovary : Oestrogen
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Option (3) is the correct answer. Parathyroid secretes parathormone. Insulin is secreted by pancreas.