Pre-copulatory behavior of whales involves pec-whetting, beak-to-genital touching, and violent head butting. a) true b) false

In natural selection, what is actually “selected? ” a) alleles are directly selected b) genotypes are directly selected c) phenotypes are directly selected d) entire populations are directly selected

All ova contain sex chromosomes corresponding to: x y xx xy

All phases of matter may have a fixed mass