Helppp with the bio test

How are gene and protein sequences used to classify organisms?

Which conditions are necessary for natural selection to occur? select all of the answers that apply. a. inheritable adaptations vary among individuals. b. the population size is increasing. c. more individuals are born than can survive. d. fitness varies among individuals. e. the environment changes suddenly and drastically.

Which is an example of a decomposer? a. bear b.algae c.grass d.bacteria d bacteria