if a prey evolves to increase its defenses, its predator often evolves to counteract this change. a. True b. False

a. True

Explanation:  

Coevolution is a biological process where pairs of species or among groups of species reciprocally affect each other's evolution through natural selection. This process produces genetic changes in the traits of interacting species that are a consequence of reciprocal adaptation between these interacting taxa. Coevolution occurs when species are ecologically intimate (i.e., they interact with one another), such as the interaction between hosts and parasites or predators and prey.

9.9 years

a = p(1 + rt) . . account balance after time t at rate r starting with principal p

3000 = 2500(1 + 0.0202t) . . filling in the given numbers

1.2 = 1 + 0.0202t . . divide by 2500

0.2 = 0.0202t . . . subtract 1

0.2/0.0202 = t ≈ 9.901

it will take about 9.9 years for the account balance to reach $3000.

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.