Skeletal muscle is called because it is usually subject to conscious control

Which of the following are false concerning microbes? a. microbes generate oxygen through photosynthesis. b. the primary role of microbes on the planet involves causing disease in animals and humans. c. microbes produce vitamins in the intestines. d. microbes play a role in breaking down waste and decomposing dead organisms.

Environmental differences within ecosystems are generally caused by

All but one describes an effect of aging on the digestive system. a) decreased acid secretion b) decreased elasticity of stomach c) capacity to resist damage decreases d) food remains in stomach for less time