What term describes the failure of one species' sperm to fertilize the egg of a different species?

Red flowered snapdragons are crossed with white flowered snapdragons, producing all pink snapdragons in the f1 generation. what would you expect if you crossed pink with pink? 3/4, 1/4, 1/2 red, 3/4,/1/2,/1/4 pink,1/2, 3/4, 1/4 white

Idon’t know the answer and i’ve been stuck on it for a while now skskskskks

What environmental cues and landmarks do the geese use to determine the timing and direction of their migration over the mountains? how do they find their way?