Calcium ions are commonly stored in the __________ of the muscle cell.

Calcium ions are commonly stored in the __________ of the muscle cell.
  a. axon
  b. myosin
  c. sarcoplasm
  d. sarcoplasmic reticulum
  e. T tubules

Question 2

Which statement about muscle contraction is false?
  a. The sliding filament model was developed by Hugh and Andrew Huxley.
  b. Acetylcholine released into the synaptic cleft stimulates muscle contraction.
  c. During contraction, the muscle length does not change, but the actin and myosin filaments
  shorten.
  d. Once the T tubules are depolarized, they open Ca2+ channels in the sarcoplasmic
  reticulum.
  e. Cross bridges are formed between myosin and actin during muscle contraction.