The independent variable controls the dependent variables.
The correct answer is A.
Toxins and various pollutants increase in concentration through the food chain in a process called biomagnification. This means that the organisms on the top of the food chain, like the herring gull, have many times greater concentration of toxins than the lower food chain level organisms because they prey on lower food chain level organisms. If a herring gull ears 100 herrings, it will have a 100x times greater concentration of toxins in its body than a herring.
Yes I think you are right. It does not contain setae for food to travel to the anus. But it's something else that develops the food into poop and travels through anus
Hope this helps :)
A frog gets rid of it's urine through the kidneys because the heart pumps blood throughout the body, the lungs are used to take in O2 molecules and gills are use to filter out the hydrogen in HO2 so they can breathe under water. However the kidneys are part of the waste disposal system (what makes us need trip to the bathroom ever now and then) therefore that is the answer.<span />
During when we are alive, oxygen is used to make atp, and atp is used to break cross-brdiges when we are relaxing / contracting our muscles. when a person is dead then there is no oxygen but the body can still produce atp via anaerobic glycolysis, when the glycogen is depleted then no atp is produce so the the cross bridges can no logner be broken that is why skeletal muscles lock