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

Aperson with age is more likely to catch diseases that healthy people usually don’t catch.what are these infections called?

Which of these has happened to your food by the time it reaches your small intestine? a. all the macromolecules have been broken down completely. b. lipids and starches have been partially broken down. c. starches and proteins have been partially broken down. d. proteins and lipids have been broken down into subunits.

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 -