The following events are associated with muscle contraction. Which of the following best describes the order in which these events occur, following neurotransmitter release from a somatic motor neuron?
1. T tubules transmit electrical impulses throughout the muscle cell
2. myosin contacts actin and pulls it towards the center of the sarcomere
3. Acetylcholine binds to receptors on the muscle
4. Troponin-tropomyosin complex shifts to expose myosin binding sites
5. Calcium is released into the sarcoplasmic reticulum
A. 4,2,1,3,5
B. 3,5,1,2,4
C. 3,5,1,4,2
D. 1,3,5,2,4
E. 3,1,5,4,2
Answer: D. 1,3,5,2,4
You might also like to view...
Membranes of thermophilic bacteria are stabilized by phospholipids with
A. fatty acids that tend to be more saturated. B. All of the choices are correct. C. fatty acids that have more double bonds. D. fatty acids that have lower molecular weights.
The streamlined bodies seen in sharks, tuna, and dolphins best relate to
A. a recent shared common ancestor. B. dissimilar selection pressures. C. the physical properties of water. D. the need to escape fast-moving predators. E. intelligent design.
You inflate a balloon and let it go. It shoots away as air exits forcefully through the balloon's narrow opening. This most closely resembles the mode of movement seen in
A) sea anemones. B) snails. C) squid. D) nematodes.
Please read the following scenario to answer the following questions. Widow's peak, a pointed hairline on the forehead, is a genetic trait caused by a dominant allele. It can be traced back through a family's history using pedigree analysis.The pedigree shown here is of three generations of a family. Notice that some individuals (shown in gray) have a widow's peak (W = dominant allele and w = recessive allele). The genotype of Mary is Ww.
a. true
b. false