Imagine carefully weighing a metal can, leaving it out in the rain for weeks and weeks until it was very rusted, and then carefully weighing it again. Would the can be heavier or lighter after it was rusted?

Which statement describes a way in which the digestive and excretory systems work together? a. the nephrons absorb nutrients from food going to the large intestine. b. the excretory system balances blood gases in the small intestine. c. the intestinal villi filter blood and send wastes to the bladder. d. the excretory system balances the salts and water obtained from digested food

Construct at least two possible hypotheses for the student’s experiment.

How many copies of genes do gametes have?