Which of the following pairs of hormones are not antagonistic (having opposite effects) to each other?
Answer: (D) Relaxin - Inhibin. Answer: (d) Relaxin - Inhibin Solution: Antagonistic hormone pairs have opposite effects: Parathormone raises blood Ca²⁺ while Calcitonin lowers it; Insulin lowers blood glucose while Glucagon raises it; ANF lowers blood pressure while Aldosterone raises it (via Na⁺/water retention).
- A.Parathormone - Calcitonin
- B.Insulin - Glucagon
- C.Aldosterone - Atrial Natriuretic Factor
- D.Relaxin - Inhibin✓
Correct Answer
(D) Relaxin - Inhibin
Solution & Explanation
Answer: (d) Relaxin - Inhibin Solution: Antagonistic hormone pairs have opposite effects: Parathormone raises blood Ca²⁺ while Calcitonin lowers it; Insulin lowers blood glucose while Glucagon raises it; ANF lowers blood pressure while Aldosterone raises it (via Na⁺/water retention). Relaxin (relaxes pelvic ligaments at parturition) and Inhibin (inhibits FSH/gonadotropin secretion) act on unrelated targets and are NOT antagonistic, so this pair is the exception. NCERT Reference: Chapter 19, Page 247, Line(s) 15-16 — "atrial natriuretic factor (ANF), which decreases blood pressure"
