1. where does mechanical digestion begin?

a. the esophagus
b. the large intestine
c. the mouth
d. the small intestine

2. urine is excreted from the body through the

a. ureter
b. urinary bladder
c. urethra
d. renal vein

The normal shape of an enzyme is as shown in structure a. if the enzyme’s shape changes to that shown in structure b, what are two consequences of this change?

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -

Consider the following planned experiment. factor experimental group control group light exposure tots of sun tots of sun amount of water weekly weekly type of soil nutrient rich nutrient rich size of pot large which variable is being tested in this experiment? small a. size of pot b. type of soil c. light exposure d. amount of water