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 zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Hormones can be composed of

  1. Amino acid derivatives

  2. Polypeptide proteins

  3. Steroid

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hormones are also grouped into three general structures as follows:

  1. Steroid hormones are fat-soluble molecules made from cholesterol. Among these are the three major sex hormones groups: estrogens, androgens and progesterones. Males and females make all three, just in different amounts. Steroids pass into a cell's nucleus, bind to specific receptors and genes and trigger the cell to make proteins.
  2. Amino acid derivatives, such as epinephrine, are water-soluble molecules derived from amino acids (the building blocks of protein). These hormones are stored in endocrine cells until needed. They act by binding to protein receptors on the outside surface of the cell. The binding alerts a second messenger molecule inside the cell that activates enzymes and other cellular proteins or influences gene expression.
  3. Insulin, growth hormone, prolactin and other water-soluble polypeptide hormones consist of long chains of amino acids, from several to 200 amino acids long. They are stored in endocrine cells until needed to regulate such processes as metabolism, lactation, growth and reproduction.

Multiple choice zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Hormones of adrenal cortex are synthesised from

  1. Tyrosine

  2. Tryptophan

  3. Cholesterol

  4. Glycoproteins
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
A. Tyrosine is the precursor for thyroxine hormone.
B. Tryptophan is the precursor for melatonin and serotonin hormone.
C. Cholesterol is used in the synthesis of steroid hormones.
D. Glycoproteins are the proteins having carbohydrate group.
Hormones of adrenal cortex are steroid hormones. They are derived from cholesterol.
So, the correct answer is 'Cholesterol'.
Multiple choice zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Steroid hormones are derived from 

  1. Cholesterol

  2. Corticoid

  3. NAD

  4. Protein
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Steroid hormones are derived from cholesterol. They are in the form of lipids and synthesised by gonads and adrenal glands. For example. testosterone and estrogen are steroid sex hormones synthesised by gonads and corticoids (glucocorticoids, mineralocorticoids and sexocorticoids) are synthesised by adrenal cortex. The receptors for steroid hormones are located inside the cells i.e. intracellular receptors. 
So, the correct answer is 'Cholesterol'.
Multiple choice zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Steroid hormones have a _______ effect.

  1. Slow and short term

  2. Fast and short term

  3. Fast and long lasting

  4. Slow and long lasting
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Steroid hormones are derived from cholesterol. They are in the form of lipids. The receptors for steroid hormones are located in the cell i.e. they are intracellular receptors. Steroid hormones cross the cell membrane as they are lipid soluble and enter the cell where they bind with the receptors and hormone-receptor complex is formed. Thus, steroid hormones act slowly but they have along lasting effect on metabolism.
So, the correct answer is 'Slow and long lasting'.
Multiple choice zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Which one is not involved as secondary messenger in $Ca^{2+}$ mediated hormone

  1. cAMP

  2. DAG
  3. $IP _3$

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

In the signaling pathway involving calcium, cAMP, DAG, and IP3 are common second messengers. Phospholipase C is an enzyme that generates DAG and IP3, not a second messenger itself.

Multiple choice zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Which of these is a steroid hormone? 

  1. Epinephrine

  2. Thyroxine

  3. Estrogen

  4. Gonadotropin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Estrogen is a steroid hormone secreted from ovarian follicles and stimulates the development of secondary sex organs and sexual characters in females. Steroid hormones are synthesised from cholesterol. They are in the form of lipids and their receptors are located inside the cell.
Epinephrine is derived from amino acid tyrosine, thyroxine is a peptide hormone and gonadotropin is a glycoprotein.
So, the correct answer is 'Estrogen'.
Multiple choice zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Which of these is not a steroid hormone? 

  1. Aldosterone

  2. Androgen

  3. Estrogen

  4. Thyroxine
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A. Aldosterone is a mineralocorticoid hormone secreted from the adrenal cortex. It maintains the electrolyte balance in the body by reducing the loss of sodium through urine and sweat.
B. Androgen is a sexocorticoid produced by adrenal cortex. It stimulates the deposition of protein in muscles and nitrogen retention in males.
C. Estrogen is the female sex hormone secreted from ovarian follicles and stimulate the development of female secondary sex organs.
D. Thyroxine is secreted from thyroid gland. It stimulates the consumption of oxygen by metabolically active tissues and also increases the oxidation of glucose in tissues. 
Out of all these hormones, thyroxine is not a steroid hormone. Instead, it is derived from amino acid tyrosine.
So, the correct answer is 'Thyroxine'.
Multiple choice zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Which of these is a glycoprotein?

  1. Erythropoietin

  2. Insulin

  3. Oxytocin

  4. Vasopressin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Erythropoietin is a glycoprotein hormone secreted by juxtaglomerular cells of kidneys. It acts on bone marrow and stimulates the formation of red blood cells (RBCs). This process is known as erythropoiesis. Erythropoietin is secreted in response to hypoxic conditions in body as RBC carry oxygen and transport it to different parts of the body.
Insulin, oxytocin and vasopressin are peptide hormones and are composed of amino acids.
So, the correct answer is 'Erythropoietin'. 
Multiple choice zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Which of the following hormones is not chemically a glycoprotein? 

  1. Growth hormone

  2. Prolactin

  3. Luteinising hormone

  4. Estrogen
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A. Growth hormone is a glycoprotein secreted by adenohypophysis of pituitary gland which helps in growth of body.
B. Prolactin is a glycoprotein secreted by adenohypophysis of pituitary gland which stimulates production and secretion of milk.
C. Luteinising hormone is a glycoprotein secreted by adenohypophysis of pituitary gland which induced ovulation.
D. Estrogen is a steroid hormone secreted by ovaries which help in development of female sexual characters.
So, the correct answer is 'Estrogen'.
Multiple choice zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Chemically epinephrine is 

  1. Amino acid derivative

  2. Steroid

  3. Peptide

  4. Glucocorticoid

  5. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Hormones have different chemical nature depending upon the type of molecules they are made up of. Some hormones like epinephrine are amino acid derivatives. Epinephrine, also known as adrenaline is secreted from adrenal medulla. It is derived from amino acid tyrosine. It contains a nitrogen atom and hence, known as amine. Epinephrine is secreted in response to stress conditions in the body and induces fight or flight reactions in the body.
So, the correct answer is 'Amino acid derivative'.
Multiple choice zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Which of the following hormones is a steroid?

  1. Oestrogen

  2. Insulin

  3. Glucagon

  4. Thyroxine
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Steroid hormones are derived from cholesterol and are lipid-soluble molecules. Examples of steroid hormones include the sex hormones (androgens, oestrogens, and progesterone). Oestrogens helps in development and maintenance of an individual's feminine characteristics. Whereas, insulin, glucagon, and thyroxin are the protein hormone 

So, the correct answer is option A.

Multiple choice zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Which of the following hormones is a derivative of fatty acids?

  1. Gastrin

  2. Thymosin

  3. Estrogen

  4. Prostaglandins
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A. Gastrin hormone is a derivate of protein.
B. Thymosin hormone is a derivate of peptide.
C. Estrogen hormone is a derivate of steroid.
D. Prostaglandins hormone is a derivate of fatty acids.
So, the correct answer is 'Prostaglandins'.
Multiple choice zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Supra optic nuclei (in hypothalamus) secrete the hormone.

  1. ADH

  2. Oxytocin

  3. Pitocin

  4. Both (2) and (3)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The supraoptic nuclei of the hypothalamus primarily synthesize ADH (vasopressin), while the paraventricular nuclei primarily synthesize oxytocin. Both are transported to and released by the posterior pituitary.

Multiple choice zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

Steroid hormones easilu pass through the plasma membrane by simple diffusion because they _______________.

  1. Are water soluble

  2. Contain carbon and hydrogen

  3. Enter through pores

  4. Are lipid soluble
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Steroid hormones are derived from cholesterol and are hydrophobic (lipid-soluble). This property allows them to diffuse directly through the lipid bilayer of the plasma membrane.