Which of the following events occurs during the lag phase of a muscle twitch?
A. Ca2+ are pumped back into the sarcoplasmic reticulum.
B. Muscle fibers shorten.
C. Cross-bridges form, move, release, and reform many times.
D. The action potential is propagated from presynaptic to postsynaptic membrane.
E. All of these events occur in the lag phase.
Answer: D
You might also like to view...
Centrioles
A) function as pipelines to move fluid through the cell. B) hold the cell's ribosomes in place. C) are white blood cells out of vessels. D) direct the movement of DNA during cell division. E) provide shape and stability to a cell.
The muscular tube that transports materials from the oral cavity to the esophagus is the ________.
What will be an ideal response?
The two vertebrae that articulate to allow pivoting of the head are atlas and axis.
Answer the following statement true (T) or false (F)
Callopistes maculatus, the dwarf tegu, is a teiid lizard that occurs in desert habitats in Chile
A study of its daily activity cycle in summer showed a decrease in activity during midday, although the body temperatures of the lizards that were active in midday were not different from the body temperatures of lizards that were active in the morning or afternoon. That observation is not consistent with the hypothesis that midday temperatures are so high that the lizards must seek shelter to avoid overheating. Apparently dwarf tegus in this habitat are able to maintain their normal activity body temperatures throughout the day. What alternative hypothesis can you suggest to account for the decrease in activity of dwarf tegus in midday? If your hypothesis is correct, what additional concern does it suggest about the potential effect of global climate change on lizards?