Biology · General Awareness

Human Endocrine System

1,395 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 biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Consider the following statements (a-d) and select the option which includes the correct ones only.
(a) The thyroid hormone plays an important role in the maintenance of the basal metabolic rate & erythropoiesis.
(b) Glucocorticoids inhibit inflammatory reactions by suppressing the immune system and promote erythropoiesis.
(c) Androgens promote development, maturation & function of the male sex organs as well as erythropoiesis.
(d) The gastrointestinal tract not only secretes gastric inhibitory peptide but also promotes the formation of RBCs.

  1. 4

  2. 3

  3. 2

  4. 1
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
In the given question, all the statements are correct as they all mention the correct function and effect of their respective hormones.
So, the correct answer is '4'.
Multiple choice zoology control and coordination in living organisms mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Steroid hormones transmit their information by 

  1. Stimulating the receptors present on cellmembrane

  2. Entering into the cell and modifying cellular contents

  3. Entering into the cell and modifying nuclear organisation

  4. The help of an intracellular second messenger
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

There are specific receptors for the binding of hormones. Steroid hormones have nuclear receptors. These steroid hormones are composed of cholesterol a dare hydrophobic in nature. They enter the cells through cell membranes. They move towards the nucleus and bind to the respective receptor. They have the activity like repression, initiation or transcription of certain genes and products. 

So, the correct answer is option C. 

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

Read the following carefully to give the correct answer 

  1. Protein hormone interact with the intra cellular receptor

  2. Iodothyronine hormone generate secondary messenger after interaction with receptor

  3. Hormone is a cell specific

  4. Somatostatin hormone secrete only by hypothalamus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Hormones are generally cell-specific because target cells possess specific receptors that bind only to particular hormones. Protein hormones interact with membrane-bound extracellular receptors, iodothyronines act via intracellular receptors, and somatostatin is secreted by tissues outside the hypothalamus as well.

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

Tyrosine act as a precursor for which of the following hormones?

  1. Thyroid

  2. Adrenal

  3. Prolactin

  4. FSH
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Thyroxine (3,5,3',5'-tetraiodothyronine) is the thyroid hormone produced by follicular cells of the thyroid gland.
  • Thyroxine hormone is produced in the thyroid gland from tyrosine and iodine.
  • Hence the precursor for the synthesis of thyroid hormone is amino acid Throne.
  • Tyrosine (symbol Tyr or Y) or 4-dihydroxyphenylalanine is one of the 20 standard amino acids.
  • So, the correct answer is 'Thyroid'.
Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

The signal transduction of steroid hormone across cell is through

  1. Binding of hormone to the cytoplasmic receptor and the complex binds to hormone response element on DNA with promoter DNA

  2. Binding of hormone to the transmembrane receptor which initiates the production of second messenger that activates enzymes which further activates transcription factors

  3. Binding of hormone to the transmembrane receptor which diffuse inside the cell cytoplasm and then activates the enzyme necessary for the activation of transcription factors

  4. Binding of hormone to the cytoplasmic receptor that initiates the production of second messenger which activates enzymes that further activates transcription factors
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Steroid hormones, i.e., androgens, estrogens, glucocorticoids, mineralocorticoids, and progestins, bind with high affinity to their respective steroid hormone receptors (SR).


Steroid hormone receptors are found in the nucleus, cytosol, and also on the plasma membrane of target cells. They are generally intracellular receptors (typically cytoplasmic or nuclear) and initiate signal transduction for steroid hormone which leads to changes in gene expression over a time period of hours to days.

So the correct answer is ' binding of hormone to the transmembrane receptor which diffuse inside the cell cytoplasm and then activates the enzyme necessary for the activation of transcription factors'.

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

Which of the following hormones triggers the release of androgens?

  1. FSH

  2. ACTH

  3. LH

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • The hypothalamus secretes gonadotropin-releasing hormone (GnRH) which stimulates the pituitary gland into secreting luteinizing hormone (LH) and follicle-stimulating hormone (FSH). 
  • LH stimulates testicular Leydig cell secretion of Testosterone whereas FSH stimulates spermatogenesis in Sertoli cells of the seminiferous tubules. 
  • An androgen is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. 
  • The major androgen in males is testosterone. Hence,  LH hormones trigger the release of androgens.
So, the correct answer is 'LH'.

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

As per accepted concept of hormone action, if receptor molecules are removed from target organs, the target organs will

  1. Continue to respond to hormone but in opposite way

  2. Continue to respond to hormone without any difference

  3. Continue to respond to hormone but will require higher concentration

  4. Stop responding to hormone
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Hormones bind to specific proteins known as hormone receptors to produce their effects. These receptors are present on target tissues only. There are two types of receptors in target tissues:
  • Membrane bound receptors : These are present on the cell membrane of target cells.
  • Intracellular receptors: These are present inside the target cell.
When a hormone binds to its receptor, hormone receptor complex is formed. This complex leads to some biochemical changes in target tissue. Hormones regulate metabolism and physiological functions of target tissue.
Hence, if receptor molecules are removed from target organs, the target organs will stop responding to hormones.
So, the correct answer is 'Stop responding to hormone'.
Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Receptors for protein hormones are found

  1. Inside nucleus

  2. Inside cytoplasm

  3. On surface of ER

  4. On the plasma membrane of the cell
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Protein hormones are peptide hormones which are derived from amino acids. These are insoluble in lipids and hence can't enter the target cell (cell membrane is a lipid bilayer). These act as primary messengers at the surface of target cell by binding to cell surface receptors and this results in the formation of a hormone-receptor complex.
So, the correct answer is 'On the plasma membrane of the cell'.
Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

In hormone action, if receptor molecules are removed from target organ, the target organ will 

  1. Continue to respond to hormone

  2. Not respond to hormone

  3. Continue to respond but requires higher concentration

  4. Continue to respond but in the opposite way
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Hormones bind to specific proteins known as hormone receptors to produce their effects. These receptors are present on target tissues only. There are two types of receptors in target tissues:
  • Membrane bound receptors : These are present on the cell membrane of target cells.
  • Intracellular receptors: These are present inside the target cell.
When a hormone binds to its receptor, hormone receptor complex is formed. This complex leads to some biochemical changes in target tissue. Hormones regulate metabolism and physiological functions of target tissue.
Hence, if receptor molecules are removed from target organ, the target organ will not respond to hormone.
So, the correct answer is 'Not respond to hormone'.
Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Steroid hormones, estrogen and testosterone bind to

  1. Membrane ion channels

  2. Enzyme-linked membrane receptors

  3. G-Protein linked membrane receptors

  4. Cytoplasmic receptors
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hormones are of 2 types based on their chemical composition. 

  1. Protein hormones: They are build up of amino acids and are soluble in water. 
  2. Steroid hormones: They are build up of fats and are not soluble in water. 
  3. Since the steroid hormones are not soluble in water they can pass through the plasma membrane and bind to the receptors in the cytoplasm.  
So the answer is Cytoplasmic receptors. 

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

Which one of the following pairs of hormones are the examples of those that can easily pass through the cell membrane of the target cell and bind to a receptor inside it(mostly in nucleus)?

  1. Insulin, glucagon

  2. Thyroxine, insulin

  3. Somatostatin, oxytocin

  4. Cortisol, testosterone
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cortisol and testosterone are lipid soluble hormones, which can directly pass through the cell membrane of the target cell and bind with intracellular receptors. So, the correct answer is option D.

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

Steroid hormones 

  1. Work via second messenger

  2. Trigger rapid, short term response in cells

  3. Alter the activity of genes

  4. Initiate open channels in plasma membrane
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Steroid hormones are derived from cholesterol. They are in the form of lipids. Their receptors are intracellular i.e. located inside the cell. These hormones are lipid soluble and hence, cross the cell membrane easily to enter the cell. The hormone binds to receptor and a hormone-receptor complex is formed. The complex then binds to transcription factors which then bind to DNA and this causes activation and transcription of a particular gene. This leads to synthesis of specific proteins that affect the metabolism of cells.
Hence, steroid hormones alter the activity of genes.
So, the correct answer is 'Alter the activity of genes'.
Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Which of these can pass easily through cell membrane of target cells and bind to internal receptors?

  1. Thyroxine, insulin

  2. Somatostatin, Oxytocin

  3. Insulin, glucagon

  4. Cortisol, testosterone
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A. Thyroxine, insulin hormones are protein hormones. 

B. Somatostatin, oxytocin are protein hormones. 
C. Insulin, glucagon are protein hormones.
D. Cortisol, testosterone are steroid hormones. 
Steroid hormones are made up of fats and are not soluble in water, hence they can easily pass through the cell membrane.
So, the answer is Cortisol, testosterone.