The DNA of all organisms is made up of the same sugar backbone and nitrogen bases. Explain what creates differences among individuals.

Groups of organisms with low biotic potential, such as gray whales, that produce at most one offspring every other year a) are r-selected b) are k-selected c) are not subject to density-dependent limiting factors d) show the initial stages of the extinction process e) have escaped from the processes of natural selection and adaptation

Suggest why placing wheels under a heavy box reduces the neccessary force required to push it along at a constant speed.

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