Physiology The ratio of actin : troponin : tropomyosin molecules in an thin filament is: A 1:01:01 B 1:03:05 C 1:07:07 D 7:01:01 💡 Explanation The ratio of actin : troponin : tropomyosin molecules in an thin filament is: ✓ Correct Answer: D. 7:01:01