The environment can change gradually over time, such as when a pond fills in and a swamp grows in its place. this process is

a. pollution
b. ecological succession
c. adaptation
d. symbiosis

some inherited genetic mutations can be good for the offspring, so the answer is different genetic mutations cause many forms of cancer.

i believe it's c. the trait for large beaks will be passed on to future generations through natural selection.

since eventually smaller beaks would have to find another source of food or even eventually just die out from the lack of food.

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.  

answer( increase) their individual contractile activity;