Answer:
Ferns and conifers evolve in Paleozoic era
The correct answer is: C) ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient.
From the example above, we can see that the concentration of calcium is higher in the SR than in cytosol, which means that calcium is moved from the area of lower concentration (cytosol) to the area of higher concentration (SR). This movement is against the concentration gradient and that is the reason for ATPase to act. This process requires energy.
The answer would be c.uracil. rna DOES contain uracil instead of having thymine like dna, the only difference in uracil and thymine is a single methyl group.
Explanation:
HIV virus is an RNA virus