5. The environment has the greatest effect on the expression of genes when
which of the following occurs?

Nucleic acid certain protein cell membranes certain carbohydrates

Abird flies by moving its wings up and down. which two systems are most directly responsible for the movement of a bird's wings? a. skeletal and muscular systems b. respiratory and muscular systems c. skeletal and digestive systems d. respiratory and digestive systems

Agland that serves both the digestive and the endocrine systems is called