75% species go extinct to be considered a mass extinction
The answer is <span>The diploid chromosome number represents two sets of chromosomes, one from each parent, so it is always an even number.
Mentioned organisms are diploid (2n) and they have 2 sets of chromosomes in their somatic cells. However, their gametes (egg cells and sperms) are haploid (n) and have only 1 set of chromosomes.
After fertilization, a haploid egg cell from a mother and a haploid sperm from a father fuse and form diploid zygote:
n + n = 2n
Nevermind if n is odd or even number, 2n will always be even.</span>
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.
