Which muscle fibers are best suited for sprinting?
yellow fibers
motor-neuron cells
red fibers
white fibers

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.

The large increase in atmospheric carbon dioxide in the last 50 years most likely comes from a. an increase in cellular respiration b. increased decomposition by bacteria c. an increase in the burning of fossil fuels d. an increase in photosynthesis

Which of the following statements about protists are true? a.they are typically found in moist environments. b.they are all unicellular. c.they have a nucleus. d.they are all multicellular.