Which of the following statements is true regarding intracellular digestion?
a. the digestion occurs outside the cell
c. all vertebrates have intracellular digestion
b. it is mainly characterized by a lack of specialized organs
d. wastes are excreted through the anus

The famous scientist galileo galilei did several experiments with sloping planes, which he rolled metal balls down so that he could study motion. by changing the slope, he could study how the speed at which the ball rolled was affected. what was the dependent variable in galileo's experiment?