Tag: endocrine system and hormone

Questions Related to endocrine system and hormone

All of the following statements are true about hormones except

  1. They are transporated by the circulatory system

  2. They bind to receptors on target cells

  3. They must be present in large quantities to have an effect

  4. They are secreted by endocrine glands

  5. They can affect organs of the body that are far removed from their site of synthesis


Correct Option: C
Explanation:
1. Hormones are produced by specialized glands(endocrine glands) and are secreted directly into the bloodstream.
2. Hormones are transported by the bloodstream from the endocrine cells to serve as ‘chemi­cal messenger’ which act on target cells or organs by regulating the rates of specific metabolic reactions. 
3. Hormones exert their effects not where they are locally produced, but on other tissues of the body. 
4. Hormones are required in very small amounts and their effect may be excitatory or inhibitory depending upon their concentration and the physiological state of the responding tissue. Hence, All of the following statements are true about hormones except They must be present in large quantities to have an effect. 
So, the correct answer is 'They must be present in large quantities to have an effect'.  

Choose the peptide hormone from the following

  1. adrenaline

  2. Insulin

  3. Testosterone

  4. Progesterone


Correct Option: B
Explanation:

Peptide hormones are the one which have single or multiple long amino acid chain/s. Insulin is a peptide hormone with two amino acid chains, one with 21 and other with 30 amino acids. This makes option B correct. 

Identify the incorrect pair.

  1. Fatty acid- Insulin

  2. Glucose- Chitin

  3. Thymine- Nucleotide

  4. Amino acid- Hemoglobin

  5. Nitrogen- Uric acid


Correct Option: A
Explanation:

Chitin is a polymer of N-acetyl glucosamine which in turn is a derivative of glucose. 

Thymine one of the purine (nitrogenous base) that makes deoxyribonucleotide units of DNA. 
Hemoglobin has four protein subunits, two alpha-globin and two beta-globin. Uric acid is a heterocyclic compound of CHON. 
Insulin is a protein hormone secreted by the pancreas.
So, the correct answer is option A.

Chemically hormones are

  1. Biogenetic amines only

  2. Proteins, steroids and biogenetic amines

  3. Proteins only

  4. Steroids only


Correct Option: B
Explanation:

Hormones are certain essential substances in our bodies that are released by our body's endocrine system.  They are chemical messengers in our bodies that transmit messages for the action of various glands in our bodies and their secretions. 

Hormones are made up of certain chemical substances like proteins,  steroids and biogenetic amines. So, option B " proteins, steroids and biogenetic amine" is the correct option.

With increasing age, secretion of which of the following reduces to almost half?

  1. GTH

  2. Melatonin

  3. Estrogen

  4. ADH


Correct Option: C
Explanation:
The primary function of estrogen is development of female secondary sexual characters. These include breasts, endometrium, regulation of the menstrual cycle, etc. In males, estrogen regulates certain functions of the reproductive system important for maturation of sperms. The loss of estrogen is a central feature of menopause, which usually occurs around age 50. However, estrogen production begins to decline in most women before they turn 40. 
So, the correct option is 'Estrogen'.

Which hormone promotes cell division, protein synthesis
and bone growth

  1. GH (STH)

  2. PTH

  3. ADH

  4. ACTH


Correct Option: A
Explanation:

The chief function of STH (GH) is to promote synthesis and secretion of small protein hormone called insulin like growth factors (IGFs).

Epinepherine is

  1. Nephrostomal part of mesoderm

  2. Clusters of glomeruli in mammalian kidney

  3. Hormone of the adrenal gland

  4. Frontal lobe of nephritides


Correct Option: C
Explanation:

The chromatin cells of adrenal medulla synthesize two hormones adrenaline or epinephrine (80%) and noradrenaline or norepinephrine (20%).

Hormones can be composed of

  1. Amino acid derivatives

  2. Polypeptide proteins

  3. Steroid

  4. All of the above


Correct Option: D
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.

Hormones of adrenal cortex are synthesised from

  1. Tyrosine

  2. Tryptophan

  3. Cholesterol

  4. Glycoproteins


Correct Option: C
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'.

Steroid hormones are derived from 

  1. Cholesterol

  2. Corticoid

  3. NAD

  4. Protein


Correct Option: A
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'.