TestUstad

All Free Biology MCQs with Answers

Every Biology question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.

19844 questions · page 709 of 1985

7081. High level of MSH can be seen in all except:

Moderate
  • A. Addison's disease
  • B. Pregnancy
  • C. Strong sunlight exposure
  • D. Cushing's disease

Explanation: MSH increases in Addison's, pregnancy, and sunlight. In Cushing's, excess cortisol dominates, not MSH.

View full explanation →
Correct answer: Cushing's disease

7082. When secretion of ADH is increased, the amount of water reabsorbed is:

Moderate
  • A. Increased
  • B. Maintained
  • C. Decreased
  • D. Has no effect on reabsorption

Explanation: ADH increases permeability of kidney's collecting ducts, enhancing water reabsorption and reducing urine volume.

View full explanation →
Correct answer: Increased

7083. The pituitary gland releases _ and _, while ovaries produce _.

Moderate
  • A. FSH, LH, and estrogen
  • B. Estrogen, FSH and LH
  • C. LH, estrogen and FSH
  • D. FSH, estrogen and LH

Explanation: Pituitary produces FSH & LH; ovaries produce estrogen (and progesterone).

View full explanation →
Correct answer: FSH, LH, and estrogen

7084. Congenital under-secretion of thyroxine causes:

Moderate
  • A. Grave's disease
  • B. Myxedema
  • C. Addison's disease
  • D. Cretinism

Explanation: Cretinism (congenital hypothyroidism) causes stunted growth and mental retardation due to low thyroxine during fetal life.

View full explanation →
Correct answer: Cretinism

7085. In males, luteinizing hormone is also known as_.

Moderate
  • A. ACTH
  • B. ICSH
  • C. TRF
  • D. MSH

Explanation: LH in males is called Interstitial Cell Stimulating Hormone (ICSH), which stimulates Leydig cells to secrete testosterone.

View full explanation →
Correct answer: ICSH

7086. Active thyroxine is also called:

Moderate
  • A. T1
  • B. T2
  • C. T3
  • D. T4

Explanation: T3 (triiodothyronine) is the active form of thyroid hormone, more potent than T4. It directly influences metabolism and cellular activity in the body.

View full explanation →
Correct answer: T4

7087. Hormones involved in ossification of bones:

Moderate
  • A. FSH
  • B. Oxytocin
  • C. Thyroxin
  • D. Parathormone

Explanation: Thyroxine (T4) promotes bone growth and the ossification process, especially during development.

View full explanation →
Correct answer: Parathormone

7088. Brain cells fail to differentiate in:

Moderate
  • A. Cretinism
  • B. Dwarfism
  • C. Grave's disease
  • D. Addison's disease

Explanation: In congenital hypothyroidism (cretinism), brain development is impaired due to thyroxine deficiency.

View full explanation →
Correct answer: Cretinism

7089. Metamorphosis in amphibians is under control of:

Moderate
  • A. Sex hormones
  • B. Pituitary hormone
  • C. Thyroid hormone
  • D. Parathyroid hormone

Explanation: Thyroid hormones drive metamorphosis in amphibians, regulating resorption of larval organs and growth of adult organs.

View full explanation →
Correct answer: Thyroid hormone

7090. Due to hypersecretion of thyroxine, there is increased BMR and exophthalmic goiter. This occurs in:

Moderate
  • A. Addison's disease
  • B. Grave's disease
  • C. Cushing's disease
  • D. Diabetes mellitus

Explanation: Graves' disease is an autoimmune disorder causing hyperthyroidism. It leads to increased basal metabolic rate, thyroid enlargement, and exophthalmos (bulging eyes).

View full explanation →
Correct answer: Grave's disease
Start Free Biology Practice MCQs Test