Why are waves of calcium that enter cells and are propagated through the cytoplasmic compartment, as happens within the first minute or so after fertilization, generally transient?
a) The ions are changed to calcium salts as soon as they enter the cell.
b) The Ca2+ ions are rapidly pumped out of the cytosol and back into the ER and/or the extracellular space.
c) The ions are destroyed as soon as they enter the cell.
d) Option D: The Ca2+ ions are rapidly pumped out of the cytosol and back into the nucleus.
Ans: b) The Ca2+ ions are rapidly pumped out of the cytosol and back into the ER and/or the extracellular space.
You might also like to view...
An example of density-dependent regulation is shown in this graph with results from a study focusing on the giant intestinal roundworm (Ascaris lumbricoides), a parasite of humans and other mammals. Denser populations of the parasite contained fewer eggs. One possible explanation for this is that females would be smaller in more dense populations (due to limited resources) and that smaller females would have fewer eggs. This hypothesis was tested and disproved in a 2009 study which showed that female weight had no influence. Given that each female was producing fewer eggs, why was the population continuing to grow?
a. More worms were moving in from adjacent populations.
b. The population was expanding due to increased mating.
c. With lower population densities, mortality decreased.
d. Lifespans were extending due to lower egg production.
Explain what occurs in the inflammatory response to a viral or bacterial invasion
What will be an ideal response?
What type of trait includes the tailbone found in humans and other primates without tails?
What will be an ideal response?
In the spring before the leaves come out, maple trees are often tapped to collect sap to make syrup. The sugars were stored in the wood of the tree as starch and then released as temperatures rise above freezing in late winter. The resulting sucrose is released into the vessels that transport water. Which of the following would a person tap to collect sap from a maple tree?
A. phloem B. collenchyma tissue C. xylem D. parenchyma tissue E. roots