How do you think diseases can affect natural selection ?

The embryos of a bird, a reptile, and a mammal are similar in appearance. how does comparing the physical appearance of embryos of different species support the theory of evolution? a. it shows that these organisms share a common ancestor. b. it provides evidence that these organisms eat the same foods.c. it shows that these organisms share the same habitat.d. it provides evidence that these organisms suffered a genetic mutation.

Which of the following cell structures is significantly different between gram- positive and gram-negative bacteria?

How do the sperm cells get from the stigma to the ovules?