why do different people have different dna profiles?

1) they have completely different kinds of str locations
2) they have different numbers of the sam strs
3)all 300 billion base pairs are analyzed for individuals
4)pcr generates some sequences more than other sequences

The diagram shows a fossil of an ancient whale skull and a skull of a present-day whale. the ancient whale is extinct and is believed to be an ancestor of the present-day whale. what do these skulls most likely show that supports darwin’s theory of evolution? all populations can adapt and survive. only some organisms have a common ancestor. populations change slowly over time. populations rapidly become extinct.

Melting glaciers is a serious threat to the environment what is the possible consequence of melting glaciers on polar bears?

All individuals have two alleles for a given trait. according to mendel's these alleles are passed down one each from both mother and father.