Plz i forgot my book at home only t or f

What is the importantence of the carbon and nitretan cycles in the environment

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

In a cladogram, what occurs at a node? a derived trait appears. evolution is stopped. an ancestor dies. the cladogram ends. aa as s as ss what are the chances that their offspring will have sickle cell anemia? 0% 25% 50% 100%