Answer:
True. The heart contracts twice per heartbeat. One contraction is the ventricular and the other one is the artrial.
Allele frequencies in a population may change due to four fundamental forces of evolution: Natural Selection, Genetic Drift, Mutations and Gene Flow. Mutations are the ultimate source of new alleles in a gene pool. Two of the most relevant mechanisms of evolutionary change are: Natural Selection and Genetic Drift.
Gametes have a single copy of an allele for each gene while zygotes have two copies for each gene.
Substrate-Level Phosphorylation is a mode of ATP synthesis that occurs when an enzyme transfers a phosphate group from a substrate molecule to ADP.
This is from my AP Bio notes. Not 100% sure, but it does sound the closest in comparison to other processes.
