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.
What is being ask i dont understand
<span>1. The bodys nonspecific defenses against invading pathogens include ?
B.mucus, sweat, and tears
2. The body's most important nonspecific defense is ?
A. The skin, it is the first line of defense.
Hope this answers the question. Have a nice day</span>
A viroid is an infectious piece of RNA without a capsid. A viroid is an infectious RNA molecule, which is similar to a virus, however, not quite the same thing. It's smaller than a virus and has no capsid. It is a coiled "naked" RNA molecule that can affect a cell. An example of human disease that is known to be caused by Viroid is hepatitis D.