Cells use a variety of mechanisms to move molecules within, into, and out of the cell. How do these mechanisms help the specialized cells in body tissues to function?

Which of the following is an example of a non-falsifiable hypothesis? a. there is a teacup orbiting the milky way galaxy. b. there is no life on mars. c. the human species started in africa. d. humans cannot live without the amino acid methionine

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.

8) animals respond in various ways to stimuli detected through their senses. some of these responses are stimulated by the presence of danger. which of these animal responses is the best example of a response to an immediate threat? a) a rooster crows every morning at the first sign of light. b) as something approaches an octopus, it shoots a cloud of ink. c) from late fall until spring, bears hibernate to preserve energy. d) a dog is getting hot in the sunlight, so he moves to a shaded area.