NCERT Class 11-Biology: Chapter – 22 Chemical Coordination and Integration Part 6 (For CBSE, ICSE, IAS, NET, NRA 2022)

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Question 2:

A sample of urine was diagnosed to contain high content of glucose and ketone bodies. Based on this observation, answer the following:

a. Which endocrine gland and hormone is related to this condition?

b. Name the cells on which this hormone acts.

c. What is the condition called and how can it be rectified?


a. Pancreas is the gland and hormone is Insulin which is responsible for this condition. Insulin is the hormone which decreases the level of glucose in blood by increasing the rate as which glucose is transported out of blood into the cell. When insulin is not produced adequately glucose uptake is hampered and hence glucose starts appearing in urine along with ketone bodies.

b. Hepatocytes and adipocytes cells are the main cells on which insulin act. Insulin allow muscles, liver and fat cells to take up this glucose.

c. This condition causes diabetes mellitus. Diabetes mellitus is a condition in which the body does not produce enough insulin hormone which results high level of sugar in blood.

It can be controlled and treated by managing following parameters:

  • Keep blood glucose level near to normal.
  • Maintain cholesterol and triglyceride level near to normal level.
  • Maintain normal blood pressure.
  • Insulin pills injections should be taken to maintain insulin level.
  • Gene therapy is required if needed.

Question 3:

Calcium plays a very important role in the formation of bones. Write on the role of endocrine glands and hormones responsible for maintaining Calcium homeostasis.


  • Thyroid gland and parathyroid gland are responsible for maintaining calcium homeostasis.
  • Both of the glands are antagonist with each other.
  • As Calcitonin which is peptide hormone secretes from thyroid gland response to high calcium level in the blood.
  • Calcitonin decreases plasma calcium concentration by decreasing mobilization of calcium from bones.
  • Whereas parthyroid gland which secretes parathyroid hormone increases calcium level in blood.
  • Bone tissue acts as astrongreservoiur for calcium and PTH stimulates the removal of calcium from bone to increase level in blood.
  • It increases the reabsorption of calcium by renal tubules of kidney.
  • PTH is a hypercalcemic hormone. i.e.. it increases the blood calcium level.

Question 4:

Illustrate the differences between the mechanism of action of a protein and a steroid hormone.


Protein and a Steroid Hormone
Protein Hormone & Steroid Hormones
Protein hormonesSteroid hormones
(i) They interact with membrane bound receptors.(i) They interact with intracellular receptors
(ii) They generate second messenger for further action.(ii) They do not generate second messenger.
(iii) Effect of these hormones alters cellular metabolism.(iii) Effect of these hormones regulates gene expression or chromosome function.
(iv) Examples. Insulin, glucagon, etc.(iv) Examples: cortisol, testosterone, etc.