Answer:
Populations are made up of all the members of a species living in the same place at the same time. A community includes all the populations of the area. The community and the abiotic factors make up the ecosystem. An organism lives in its habitat within a community.
Explanation:
The answer is D, all of the above.
By changing the controlled variable.
Answer:
Gut Microbiome
Explanation:
This is home base for the bacteria in your digestive tract. Here, they help you break down food and turn nutrients into things your body can use. They stop growing when they run out of food, so you'll only have what you need.
Answer:
c. A piece of mesh, keeping some things out and letting some things in
Explanation:
The cell membrane of a cell is described as "selectively permeable". Permeable means things can go through it, but the word selectively is the important part. It lets things in, but it also keeps things out. This way it can regulate the different things that go in and out of the cell. It allows certain molecules that provide the cell nourishment and other things that help it function, and at the same time, it allows waste to move out of the cell. Not all needed molecules can go through the "mesh-like" membrane, that why some of them need help.