From the 2000 IBO theory paper A:

98. A nerve-skeletal muscle isolated preparation is placed in a Ca2+ -free medium appropiate for its survival. If the nerve is electrically
stimulated, which of the following events will occur?
___A) The muscle will not be stimulated
___B) The muscle will be stimulated but will not contract
___C) The muscle will be both stimulated and contract
___D) The muscle will not be stimulated, but even if it is, it will not contract
___E) The muscle may be stimulated, and may contract but it will not relax

Question

From the 2000 IBO theory paper A:

98. A nerve-skeletal muscle isolated preparation is placed in a Ca2+ -free medium appropiate for its survival. If the nerve is electrically
stimulated, which of the following events will occur?
___A) The muscle will not be stimulated
___B) The muscle will be stimulated but will not contract
___C) The muscle will be both stimulated and contract
___D) The muscle will not be stimulated, but even if it is, it will not contract 
___E) The muscle may be stimulated, and may contract but it will not relax

anonymous · Answer

I thought it was C because muscle cells store calcium in the sacromerial reticulum but the answer sheet said A.

caozeyuan · Answer

Ca2+ in the SR may be released only when it is stimulated by Ca2+ influx from the outside. However, there is no Ca2+ outside, hence SR will not release its Ca2+ so muscle cannot contract. Stimulation does not occur because there is no outside Ca2+

anonymous · Answer

ooh thank you soo much!!! I was stuck with this question for so long