Organs, such as the stomach and the small and large intestines, are lined with smooth muscle tissue. these organs, due to the muscular contractions of their walls, involuntarily a) grind food into smaller pieces. b) move food through the digestive tract. c) add liquids to food to make it a slurry. d) supply digestive enzymes that aid in digestion.

Once an egg cell is fertilized by sperm, the cell then, as the embryo develops, it receives nourishment and eliminates wastes by transferring substances from its blood to its mother's blood. a. becomes a fetus immediately and exits the womb b. begins to divide and implants itself in the wall of the uterus c. remains in the uterus without dividing for several months d. travels back to the ovaries until the fetus is developed