Ais anything that happens as a result of something that happens. for example, if you hit your thumb with a hammer, it hurts!
a. fact
b. rule

Natural selection changes allele frequencies because some survive and reproduce more successfully than others.

Which of the following is a reason why early living organisms on earth could not have survived on the surface? 1. the lack of an ozone layer 2. the lack of oxygen in the atmosphere 3. the fact that these organisms were single-celled

Need with these questions . need the answers in a rush for these questions are the answers i put down are correct or not? ?