The system breaks down food, and the system transports nutrients to the cells of the body. a. circulatory; digestive b. digestive; nervous c. digestive; circulatory d. nervous; excretory

Which of the following describes a negative feedback loop? when the heart rate is too high, the body sends hormones that continually increase the heart rate higher. when a pregnant woman is in labor, the body sends hormones that increase the intensity of contractions, which then increases the secretion of the same hormones. when blood sugar is too low, the body sends hormones that raise blood sugar until it reaches a typical level and hormone secretion slows. when a person is jogging, the body sends hormones that continually decrease the rate of oxygen supply to the legs.

Which are characteristics of flukes? check all that apply. a they are free living. b they are a type of flatworm. c they reproduce sexually. d they have eyespots. e they are segmented.

Organisms may contain up to five levels of organization within their bodies. which level of organization is shown by the liver? a. tissue b. organ c. organism d. organ system