One part of an ecosystem can affect a completely different part of that ecosystem. for example, a change in the climate can affect the rabbits, or the mosquitoes can affect the deer.

a: true
b: false

the answer is:

carbon dioxide

i think it is dna, i'm not totally sure but i think it might be.

the wetland preservation movement began in the u.s. in earnest with the clean water act (cwa) of 1972. although not specifically written to protect wetlands, the cwa is comprised of a series of regulations designed to prevent pollutants from contaminating u.s. waters.