In the cardiac cycle,
a. the right atrium and the right ventricle contract simultaneously.
b. the two atria relax while the two ventricles contract.
c. the left atrium contracts before the right atrium.
d. all four chambers of the heart contract at the same time.
e. all four chambers of the heart are in systole at the same time.

In cattle a single gene with two alleles determines fur color the fur can be red white or roan roan fur has both red and white hair which of the following statements is true a the allele for roan fur color is dominant over red and white fur color b the allele for red fur color is dominant over white and roan fur color c the roan and white alleles are expressed independently of the other d the red and white alleles are expressed independently of each other