NEET 2025 MCQ with Answer Explanation : Chemical coordination and Integration.

Question 71:
Which hormone increases during fasting to promote energy mobilization?

A) Insulin
B) Glucagon
C) Cortisol
D) Thyroxine

Answer: B) Glucagon

Explanation: Glucagon increases during fasting to promote the mobilization of energy by stimulating glycogenolysis and gluconeogenesis.

Question 72:
Which hormone is released in response to low blood oxygen levels?

A) Erythropoietin
B) Insulin
C) Cortisol
D) Thyroxine

Answer: A) Erythropoietin

Explanation: Erythropoietin is released by the kidneys in response to low oxygen levels, stimulating the production of red blood cells.

Question 73:
What effect does adrenaline have on the cardiovascular system?

A) Decreases heart rate
B) Increases heart rate
C) Causes vasodilation
D) Lowers blood pressure

Answer: B) Increases heart rate

Explanation: Adrenaline increases heart rate and blood pressure to prepare the body for a rapid response during stressful situations.

Question 74:
Which hormone stimulates the release of cortisol from the adrenal cortex?

A) Growth hormone (GH)
B) Adrenocorticotropic hormone (ACTH)
C) Thyroid-stimulating hormone (TSH)
D) Luteinizing hormone (LH)

Answer: B) Adrenocorticotropic hormone (ACTH)

Explanation: ACTH stimulates the adrenal cortex to release cortisol and other glucocorticoids.

Question 75:
Which hormone is responsible for the regulation of the body’s metabolic rate?

A) Insulin
B) Cortisol
C) Thyroxine
D) Testosterone

Answer: C) Thyroxine

Explanation: Thyroxine regulates the metabolic rate and is essential for growth and development.

Question 76:
Which hormone is primarily involved in fat metabolism and energy regulation?

A) Insulin
B) Glucagon
C) Leptin
D) Thyroxine

Answer: C) Leptin

Explanation: Leptin regulates fat storage and energy balance by signaling the brain to inhibit hunger and increase energy expenditure.

Question 77:
Which hormone is secreted by the pancreas in response to high blood sugar levels?

A) Glucagon
B) Cortisol
C) Insulin
D) Epinephrine

Answer: C) Insulin

Explanation: Insulin is released by the pancreas in response to high blood sugar levels to facilitate glucose uptake by cells.

Question 78:
Which hormone is primarily responsible for stimulating ovulation?

A) Progesterone
B) Follicle-stimulating hormone (FSH)
C) Luteinizing hormone (LH)
D) Estrogen

Answer: C) Luteinizing hormone (LH)

Explanation: Luteinizing hormone (LH) triggers ovulation and stimulates the production of progesterone by the ovaries.

Question 79:
Which hormone is responsible for the regulation of sodium and potassium levels?

A) Insulin
B) Cortisol
C) Aldosterone
D) Thyroxine

Answer: C) Aldosterone

Explanation: Aldosterone helps regulate sodium and potassium levels in the body, affecting blood pressure and fluid balance.

Question 80:
What is the effect of insulin on fat cells?

A) Increases fat breakdown
B) Promotes fat storage
C) Decreases fat storage
D) Has no effect

Answer: B) Promotes fat storage

Explanation: Insulin promotes fat storage in adipose (fat) cells by facilitating the uptake of glucose and fatty acids for energy storage.