What happens to e. coli when lactose is not present?

a. the enzymes needed to break down lactose are continually produced.
b. the genes that produce the enzymes needed to break down lactose are not expressed.
c. e. coli is not able to survive without lactose.
d. the genes required to produce the enzymes that break down lactose are destroyed.

The pharynx is the structure in the body that serves as a pathway of both air and food. how does the body make sure that food does not get into the lungs? the salivary glands secrete enzymes that pull food out of the air pathway. the small intestine pushes the air out of the digestive system. the pancreas breaks down food in the air pathway. the epiglottis closes the air pathway so that food will not enter it.