What is the structure called, found in Agnathans, which will become the endoskeleton in more evolutionary advanced organisms?

Which statements correspond to cellular respiration? co2 diffuses passively into the cell. co2 diffuses passively out of the cell. co2 must be pumped out of the cell. o2 diffuses passively when produced inside the cell. o2 diffuses passively when converted to co2. o2 is pumped in and forces co2 out.

If the frequency of the p allele is .63 in the population then what is the frequency of the q allele?

Someone me with this: a mineral' is determined by its actomic structure.