Why is the island biogeography theory a theory but not a fact?

Contrast how pollination is different among gymnosperms and angiosperms.

In pea plants, the allele for inflated pod seed, i, is dominant over the allele for constricted pod seed, i. the punnett square shows a cross for this trait. which offspring will be homozygous dominant

About how many years does it take for one cycle of surface water to become deep water and then surface water again in the oceans? 101001,000