The heart has four valves that control the flow of blood. two of the valves (the av valves) normally prevent blood from flowing upwards. the other two valves (semilunar valves) normally prevent blood from flowing downwards. the av valves and semilunar valves have different shapes. which principle of anatomy and physiology does this example represent?

Plz fast biotechnology is a growing field of applied biology. many crops such as corn have been engineered to be resistant to herbicides. therefore farmers can spray these chemicals to kill weeds growing near the crop without worries of killing the crop itself how does this type of biotechnology work? a. by changing the genetic make up of the crops. b. by causing the crops to kill the weeds. c. by changing the type of crops used. d. by changing the location of the crops.

Differentiate renewable and nonrenewable resources

Which of the following terms would bb represent in an organism? a.phenotype b.genotype c.genetics