Ca²⁺ ions for muscle contraction are released from the

  1. mitochondria
  2. sarcoplasmic reticulum
  3. nucleus
  4. T-tubules
Answer

B) sarcoplasmic reticulum

The SR stores Ca²⁺. AS & A Level Biology · Topic 15 Control and Coordination · 15.1 Control and coordination in mammals

Biology MCQ · More A Level Biology: Control and coordination MCQs · Practise