On the way to school, a student rides his bike to the bus stop. He then waits a few minutes for the bus to come
and rides the bus to school. The bus stops at school, and
he walks from the parking lot to his first class. Is the
graph of his distance always increasing? Explain.

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.

When does the circulatory system work with the respiratory system? a. during blood cell formation b. during cellular respiration c. during intestinal digestion d. during a viral infection

The response is the basis for vaccination. primary secondary tertiary none of the above