Part 3: Pineal, Thyroid, Parathyroid – Structure, Hormones, Functions, Disorders
Part 3 (25 MCQs) on Pineal, Thyroid, Parathyroid – Structure, Hormones, Functions, Disorders from Chapter 22: Chemical Coordination and Integration (NCERT Class 11 + NEET UG).
Part 3: Pineal, Thyroid, Parathyroid – Structure, Hormones, Functions, Disorders
Q1. The hormone secreted by pineal gland is:
a) Cortisol
b) Melatonin
c) Thyroxine
d) Aldosterone
Answer: b) Melatonin
- ✅ Pineal gland → melatonin → regulates circadian rhythm.
Q2. Melatonin is responsible for:
a) Blood sugar regulation
b) Sleep-wake cycle and seasonal reproduction
c) Water balance
d) Blood pressure
Answer: b) Sleep-wake cycle and seasonal reproduction
- ✅ Melatonin controls biological clock & photoperiodic responses.
Q3. Which gland is called “Adam’s apple”?
a) Adrenal
b) Pituitary
c) Thyroid
d) Pineal
Answer: c) Thyroid
- ✅ Thyroid enlarges in the front of neck → Adam’s apple.
Q4. Which element is essential for thyroid hormone synthesis?
a) Calcium
b) Iodine
c) Sodium
d) Iron
Answer: b) Iodine
- ✅ Thyroxine (T₃/T₄) requires iodine.
Q5. Deficiency of iodine leads to:
a) Cretinism
b) Goiter
c) Gigantism
d) Tetany
Answer: b) Goiter
- ✅ Iodine deficiency → enlarged thyroid (goiter).
Q6. Thyroid secretes:
a) Thyroxine, calcitonin
b) Cortisol, aldosterone
c) Insulin, glucagon
d) Prolactin, oxytocin
Answer: a) Thyroxine, calcitonin
- ✅ Thyroid secretes T₃, T₄ (metabolism) & calcitonin (lowers Ca²⁺).
Q7. Hypothyroidism in children causes:
a) Myxedema
b) Cretinism
c) Gigantism
d) Acromegaly
Answer: b) Cretinism
- ✅ Mental retardation, dwarfism due to hypothyroidism in children.
Q8. Hypothyroidism in adults causes:
a) Cretinism
b) Myxedema
c) Goiter
d) Acromegaly
Answer: b) Myxedema
- ✅ Lethargy, low BMR, puffiness due to low thyroid hormones in adults.
Q9. Hyperthyroidism leads to:
a) Goiter
b) Exophthalmic goiter (Graves’ disease)
c) Diabetes insipidus
d) Addison’s disease
Answer: b) Exophthalmic goiter (Graves’ disease)
- ✅ Excess thyroxine → protruding eyes, high BMR.
Q10. Calcitonin hormone is secreted by:
a) Parathyroid
b) Thyroid
c) Pituitary
d) Pancreas
Answer: b) Thyroid
- ✅ Calcitonin lowers blood Ca²⁺, secreted by thyroid parafollicular cells.
Q11. Calcitonin function is:
a) Increases blood Ca²⁺
b) Decreases blood Ca²⁺
c) Increases blood glucose
d) Increases blood Na⁺
Answer: b) Decreases blood Ca²⁺
- ✅ Calcitonin reduces calcium levels by deposition in bone.
Q12. Parathyroid glands are located:
a) On thyroid gland posteriorly
b) On adrenal gland
c) Near pituitary
d) On pancreas
Answer: a) On thyroid gland posteriorly
- ✅ 4 parathyroids embedded in thyroid posterior surface.
Q13. Hormone secreted by parathyroid is:
a) Calcitonin
b) Parathormone (PTH)
c) Insulin
d) GH
Answer: b) Parathormone (PTH)
- ✅ PTH increases blood Ca²⁺.
Q14. Parathormone acts on:
a) Kidney, bone, intestine
b) Heart and brain
c) Muscle and nerves
d) Pancreas only
Answer: a) Kidney, bone, intestine
- ✅ PTH increases Ca²⁺ reabsorption in kidney, bone resorption, and intestinal absorption.
Q15. Deficiency of PTH causes:
a) Osteoporosis
b) Hypocalcemia → tetany
c) Diabetes mellitus
d) Goiter
Answer: b) Hypocalcemia → tetany
- ✅ Low Ca²⁺ → muscle spasms.
Q16. Excess of PTH causes:
a) Bone softening & kidney stones
b) Gigantism
c) Cretinism
d) Diabetes insipidus
Answer: a) Bone softening & kidney stones
- ✅ Hyperparathyroidism → demineralized bones, high blood Ca²⁺.
Q17. Goiter can be prevented by:
a) Vitamin D supplementation
b) Iodized salt
c) Insulin therapy
d) Calcium tablets
Answer: b) Iodized salt
- ✅ Iodine prevents goiter.
Q18. Which hormone regulates basal metabolic rate?
a) GH
b) Thyroxine
c) Insulin
d) Cortisol
Answer: b) Thyroxine
- ✅ Thyroxine controls metabolism.
Q19. Thyroxine deficiency during pregnancy affects:
a) Fetus brain development
b) Fetus bone length only
c) Placenta formation
d) Pancreas function
Answer: a) Fetus brain development
- ✅ Maternal hypothyroidism → impaired mental development in fetus.
Q20. The thyroid gland secretes two iodine-containing hormones:
a) TSH and thyroxine
b) T₃ (triiodothyronine) and T₄ (thyroxine)
c) T₁ and T₂
d) Calcitonin and PTH
Answer: b) T₃ (triiodothyronine) and T₄ (thyroxine)
- ✅ T₃ (active form), T₄ (prohormone).
Q21. Exophthalmic goiter is caused by:
a) Hypothyroidism
b) Hyperthyroidism
c) Hypoparathyroidism
d) Hypopituitarism
Answer: b) Hyperthyroidism
- ✅ Graves’ disease = hyperthyroidism with protruded eyes.
Q22. Which hormone maintains calcium-phosphorus balance?
a) Calcitonin and PTH
b) Cortisol and aldosterone
c) Insulin and glucagon
d) GH and prolactin
Answer: a) Calcitonin and PTH
- ✅ Both regulate Ca²⁺-P balance (antagonistic).
Q23. In absence of thyroid, a frog tadpole fails to:
a) Grow
b) Metamorphose
c) Reproduce
d) Survive
Answer: b) Metamorphose
- ✅ Thyroxine needed for metamorphosis.
Q24. The thyroid gland is controlled by:
a) ACTH
b) TSH
c) FSH
d) PTH
Answer: b) TSH
- ✅ TSH from pituitary regulates thyroid.
Q25. Cretinism is characterized by:
a) High BMR, excitability
b) Stunted growth, mental retardation
c) High blood sugar
d) Excessive sweating
Answer: b) Stunted growth, mental retardation
- ✅ Childhood hypothyroidism → cretinism.
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