Chemical Coordination And Integration Multiple Choice Questions

Q1. Which of the following is an accumulation and release centre of neurohormones?

  • Posterior pituitary lobe
  • Intermediate lobe of the pituitary
  • Hypothalamus
  • Anterior pituitary lobe

Solution

All secretion by the pituitary gland is controlled by a hormonal signal from the hypothalamus. The neurohormones are secreted and accumulated by the hypothalamus.

Q2. mso-ansi-language:EN-GB”>In the mechanism of action of a protein hormone, one of the second messengers is

  • Cyclic AMP
  • Insulin
  • T3
  • Gastrin

Solution

Cyclic AMP gets activated inside the cell when the protein hormone binds itself to the receptor on the cell membrane.

Q3. A common scent-producing gland among mammals is

  • Anal gland
  • Prostate gland
  • Adrenal gland
  • Bartholin gland

Solution

Scent or musk glands are located around the face, feet or anus of many mammals. These secrete pheromones which are involved in defence, recognition and territorial behaviour.

Q4. mso-ansi-language:EN-GB”>An adenohypophysis hormone which is regulated by the feedback mechanism is

  • Oxytocin
  • TSH
  • Vasopressin
  • Cortisone
  • Calcitonin

Solution

Thyroid-stimulating hormone (TSH) is secreted by the adenohypophysis. It controls the secretion of thyroid hormones by the thyroid gland.

To maintain the levels of thyroxine in blood under normal, the secreted thyroxine shows a negative effect of the adenohypophysis which inhibits the secretion of TSH.

Q5. Which of the following induces parturition?

  • Vasopressin  
  • Oxytocin  
  • GH  
  • TSH  

Solution

Oxytocin is secreted by the posterior lobe of the pituitary gland. It increases the contraction of the uterine muscles during parturition.

Q6.

Erythropoietin is a

  • Peptide hormone
  • Steroid hormone
  • Amine hormone
  • Both 1 and 3 above

Solution

Erythropoietin is a peptide hormone. It is secreted by the juxtaglomerular cells of the kidneys. This hormone is required for the formation of red blood cells.

Q7. Other than ANF, the other hormone secreted by the heart is

  • Calcitrol
  • Oxytocin
  • Epinephrine
  • Aldosterone

Solution

The heart also secretes oxytocin, commonly referred to as the ‘love’ or bonding hormone.

Q8.Which one of the following pairs correctly matches a hormone with a disease resulting from its deficiency?

  • Thyroxine – Tetany  
  • Parathyroid hormone – Diabetes mellitus  
  • Luteinising hormone – Failure of ovulation  
  • Insulin – Diabetes insipidus  

Solution

Luteinising hormone (LH) is secreted by the pars distalis or anterior pituitary.

In males, LH stimulates the synthesis of androgens from the testes. In females, it is responsible for the ovulation and release of the mature Graafian follicle, formation of the corpus luteum etc.

Low LH levels result in the failure of ovulation.

Q9. mso-ansi-language:EN-GB”>Which of the following hormones helps in the contraction of the uterus during childbirth?

  • ADH
  • Androgen
  • Oxytocin
  • Glucocorticoid

Solution

Oxytocin is secreted by the posterior pituitary.

It is a peptide hormone which stimulates the contraction of uterine muscles during birth.

Q10. Insulin is

  • Vitamin
  • Lipid
  • Hormone
  • Enzyme

Solution

Insulin is the earliest known hormone which is also called the hypoglycaemic factor as it decreases the glucose level in the blood and prevents the occurrence of diabetes. It is secreted by β-cells of the islets of Langerhans.

Q11. Which hormone is responsible for the rise in blood sugar?

  • Glucagon
  • Somatostatin
  • Insulin
  • All of the above

Solution

Glucagon is responsible for the rise in blood sugar levels.

Q12. Adrenaline directly affects

  • SA node
  • β-cells of Langerhans
  • Dorsal root of the spinal cord
  • Epithelial cells of the stomach

Solution

Adrenaline or epinephrine is secreted by the adrenal medulla. This hormone is responsible for the increase in heart rate, breathing and blood glucose level.

Q13. mso-ansi-language:EN-GB”>In adults, hypothyroidism causes

  • Obesity
  • Diabetes
  • Cretinism
  • Myxoedema

Solution

Myxoedema is caused by the deficiency of thyroxine in adults. It is also called Gull’s disease.

The individual has a puffy appearance, lack of alertness and low intelligence quotient. The person also suffers from low body temperature, low heart rate and reproductive failure.

Q14. During emergency, which of the following hormones is secreted?

  • Aldosterone  
  • Thyroxine  
  • Adrenaline  
  • Calcitonin  

Solution

Adrenaline is secreted by the adrenal medulla. It mainly acts on smooth muscles, cardiac muscles, blood vessels, skeletal muscles and fat cells.

Adrenaline initiates the stress responses in the body.

It increases heart rate, blood pressure, metabolic rate, dilates blood vessels and increases the breathing rate and hence oxygen consumption and glucogenesis (i.e. the formation of glucose by the breakdown of liver glycogen), elevating the blood glucose levels.

Q15. mso-ansi-language:EN-GB”>Chemically, hormones are

  • Proteins only
  • Steroids only
  • Biogenic amines only
  • Proteins, steroids and biogenic amines

Solution

On the basis of chemical nature, hormones are categorised as steroids (cortisol), proteins (insulin) and biogenic amines (epinephrine).

Q16. Hormones are called chemical signals which stimulate specific target tissues. Their specificity is due to the presence of signal receiving ‘receptors’ only in the respective target tissues. Where are these receptors present in case of hormones of protein nature?

  • Extracellular matrix
  • Blood
  • Plasma membrane
  • Nucleus

Solution

The hormones of protein nature cannot cross the plasma membrane. Hence, these hormones bind on the protein receptors present on the plasma membrane.

As soon as they bind to the receptors, secondary messengers are activated in the cell which express the effects of hormones.

Q17. mso-ansi-language:EN-GB”>The steroid responsible for the balance of water and electrolytes in our body is

  • Insulin
  • Melatonin
  • Testosterone
  • Aldosterone

Solution

Aldosterone is a steroid hormone secreted by the adrenal cortex. It acts on kidney tubules to maintain the balance of sodium and potassium ions.

Q18. According to the accepted concept of hormone action if receptor molecules are removed from target organs, then the target organ will

  • not respond to the hormone
  • continue to respond to the hormone without any difference
  • continue to respond to the hormone but in the opposite way
  • continue to respond to the hormone but will require higher concentration

Solution

Hormones are released in the blood, but each hormone stimulates only a specific target organ to initiate a specific response. It is due to the presence of a specific receptor protein in a specific target cell. If these receptor molecules are removed from the target organs, then the organ will not respond to the hormone.

Q19. Damage to the thymus in a child may lead to

  • A reduction in haemoglobin content of blood  
  • A reduction in stem cell production  
  • Loss of antibody-mediated immunity  
  • Loss of cell-mediated immunity  

Solution

The thymus secretes the hormone thymosin which stimulates the differentiation of T-lymphocytes. T-lymphocytes provide cell-mediated immunity. In old age, the thymus gland degenerates; hence, immune responses in old people are weak.

Hence, damage to the thymus gland in a child will hamper the differentiation of T-lymphocytes which provide immunity.

Q20. mso-ansi-language:EN-GB”>Which one of the following hormones is a modified amino acid?

  • Prostaglandin
  • Oestrogen
  • Epinephrine
  • Progesterone

Solution

Modified amino acids are derived from a single amino acid.

Epinephrine and norepinephrine are catecholamines; both are modified amino acids derived from tyrosine.

Q21. A hormone responsible for the normal sleep-wake cycle is

  • Epinephrine  
  • Gastrin  
  • Melatonin  
  • Insulin  

Solution

Melatonin is secreted the pineal glands. The hormone’s function is to control the biological rhythm or the diurnal rhythm of our body.

Q22. mso-ansi-language:EN-GB”>FSH is secreted by

  • Anterior lobe of pituitary
  • Hypothalamus
  • Gonads
  • Posterior lobe of pituitary

Solution

Follicle-stimulating hormone (FSH) is secreted by the par distalis or the anterior pituitary.

In males, FSH regulates spermatogenesis. In females, it stimulates the growth and development of the ovarian follicles.

Q23. mso-ansi-language:EN-GB”>Which out of the following pairs is incorrectly matched?

  • Insulin – Diabetes mellitus (disease)
  • Glucagon – Beta cells (source)
  • Somatostatin – Delta cells (source)
  • Corpus luteum – Relaxin (secretion)

Solution

Glucagon is a polypeptide hormone which is secreted by the α-cells of pancreas. This hormone is responsible for raising the blood glucose level by breaking down glycogen into glucose and promoting the conversion of non-carbohydrate substances into glucose.

β-cells secrete insulin which lowers the blood glucose level.

Q24. Feeling the tremors of an earthquake, a scared resident of the seventh floor of a multi-storeyed building starts climbing down the stairs rapidly. Which hormone initiated this action?

  • Thyroxine
  • Adrenaline
  • Glucagon
  • Gastrin

Solution

Adrenaline is responsible for this action as the hormone is known as 3F hormone—fright, fight and flight.

Q25. Diabetes is due to

  • Iodine deficiency
  • Hormonal deficiency
  • Na+ deficiency
  • Enzyme deficiency

Solution

Diabetes mellitus occurs because of a deficiency of the insulin hormone which is secreted by the islets of Langerhans of the pancreas.

Q26. Progesterone, which is the most important component of oral contraceptive pills, prevents pregnancy by

  • Preventing the formation of the egg
  • Preventing the cleavage of the fertilised egg
  • Creating an unfavourable chemical environment for the sperms to survive in the female reproductive tract
  • Blocking ovulation

Solution

Contraceptive pills contain oestrogen and progesterone which disturb the normal menstrual cycle to prevent ovulation. They inhibit the pituitary from secreting FSH and LH and block ovulation.

Q27. mso-ansi-language:EN-GB”>A steroid hormone which regulates glucose metabolism is

  • Cortisone
  • Cortisol
  • Corticosterone
  • ll-Deoxycorticosterone

Solution

Steroids are lipid hormones which are derived from cholesterol.

Cortisol is secreted by the middle layer (i.e. zona fasciculata) of the adrenal cortex.

Cortisol promotes gluconeogenesis (i.e. the formation of glucose from non-carbohydrates such as proteins). It also stimulates proteolysis and lipolysis.

Q28. Select the answer which correctly matches the endocrine gland with the hormone it secretes and its deficiency symptom.

  •  Endocrine gland     Hormone     Function/deficiency symptoms     Posterior pituitary     Growth hormone (GH)     Oversecretion stimulates abnormal growth        
  •  Endocrine gland     Hormone     Function/deficiency symptoms     Thyroid gland     Thyroxine     Lack of iodine in the diet results in goitre        
  •  Endocrine gland     Hormone     Function/deficiency symptoms     Corpus luteum     Testosterone     Stimulates spermatogenesis        
  •  Endocrine gland     Hormone     Function/deficiency symptoms     Anterior pituitary     Oxytocin     Stimulates uterus contraction during childbirth        

Solution

The thyroid gland secretes thyroxine. Synthesis of thyroxine requires iodine. Hence, lack of iodine results in hypothyroidism deficiency, i.e. simple goitre.

Q29. Thymosin is responsible for

  • Raising the blood sugar level  
  • Raising the blood calcium level  
  • Increased production of T lymphocytes  
  • Decrease in blood RBC  

Solution

Thymosin is secreted by the thymus gland. This hormone is responsible for the differentiation of T-lymphocytes which provide cell-mediated immunity.

Q30. Sertoli cells are regulated by the pituitary hormone known as

  • FSH
  • GH
  • Prolactin
  • LH

Solution

Sertoli cells protect the spermatids and provide nutrients to both developing and mature spermatozoa. They are regulated by follicle-stimulating hormone (FSH) as FSH receptors are confined to Sertoli cells.

Q31. mso-ansi-language:EN-GB”>Progesterone is secreted by

  • Corpora radiata
  • Corpus albicans
  • Corpus luteum
  • Corpus callosum

Solution

The corpus luteum is a yellowish mass left behind after ovulation. It secretes progesterone which supports pregnancy and also prepares the mammary glands for lactation.

Q32. Prostaglandins are

  •  Amino acid
  •  Steroid
  •  Fatty acid
  •  Carbohydrate

Solution

Prostaglandins are fatty acids derived from arachidonic acid. They are released by every organ, and they perform various roles in immunity, reproduction, digestion, respiration, circulation, excretion etc.

Q33. Steroid hormones are water-insoluble hormones. They attach themselves to the receptors once they enter the cell. These receptors are

  • Protein receptors present in the cytoplasm.
  • Protein receptors present in the cytoplasm or the nucleus.
  • Carbohydrate receptors present in the cytoplasm.
  • Carbohydrate receptors present in the cytoplasm or the nucleus.

Solution

Steroids are water-insoluble hormones. They travel in the blood by attaching themselves to blood protein carriers. When they reach the target cell, they dissociate from the protein carrier and enter the cell. In the cell, some steroids bind to specific receptor proteins in the cytoplasm and enter the nucleus, while some directly enter the nucleus and then bind to the specific receptor protein to form a hormone-receptor protein complex.

Q34. mso-ansi-language:EN-GB”>Choose the correct answer among the following options:

EpinephrineIncrease in muscle growth
TestosteroneDecrease in blood pressure
GlucagonDecrease in liver glycogen content
Atrial natriuretic factorIncrease in heart beat
  • A-ii, B-i, C-iii, D-iv
  • A-iv, B-i, C-iii, D-ii
  • A-i, B-ii, C-iii, D-iv
  • A-i, B-iv, C-ii, D-iii

Solution

Epinephrineiv. Increase in heart beat
Testosteronei. Increase in muscle growth  
Glucagoniii. Decrease in liver glycogen content
Atrial natriuretic factorii. Decrease in blood pressure

Q35. mso-ansi-language:EN-GB”>Cortisol is secreted from

  • Pancreas
  • Thyroid
  • Adrenal
  • Thymus

Solution

Cortisol, a steroid, is secreted by the adrenal cortex. It acts on the kidneys or renal tubules to maintain the Na+-K+ balance. It is also involved in maintaining the cardiovascular system.

Q36. When both ovaries are removed from rat, which hormone is decreased in blood?

  • Oxytocin
  • Prolactin
  • Oestrogen
  • Gonadotropin-releasing factor

Solution

If both ovaries are removed from rat, then the blood plasma level of oestrogen will be affected as it is produced by the theca interna cells of the Graafian follicles.

Q37. mso-ansi-language:EN-GB”>Which of the following glands is not an endocrine gland?

  • Pancreas
  • Pineal gland
  • Testes
  • Parotid gland

Solution

The parotid gland is a salivary gland which releases its secretion into the mouth through a duct.

The pineal gland and testes are endocrine glands, while the pancreas is an exocrine as well as an endocrine gland.

Q38. mso-ansi-language:EN-GB”>The hormone responsible for ovulation is

  • LH
  • FSH
  • Progesterone
  • Testosterone

Solution

Luteinising hormone (LH) is secreted by the pars distalis or anterior pituitary.

LH stimulates the synthesis of androgens from the testes in males, while it is responsible for ovulation and the release of mature Graafian follicle, formation of the corpus luteum etc. in females.

Low LH levels result in the failure of ovulation.

Q39. mso-ansi-language:EN-GB”>The corpus luteum secretes a hormone called

  • Prolactin
  • Progesterone
  • Aldosterone
  • Testosterone

Solution

The corpus luteum is a yellowish mass left after the ovulation of the mature ovarian follicle.

It secretes progesterone which acts on the uterus and prepares its endometrial lining for pregnancy.

It also acts on mammary glands.

Q40. Delta cells secrete

  • Glucagon
  • Somatostatin
  • Insulin
  • Cortisol

Solution

Delta cells in the islets of Langerhans secrete somatostatin.