Video Transcript
What are the products of
meiosis? (A) Two cells, each containing the
same number of chromosomes as the original, parent, cell. (B) Four cells, each containing
double the number of chromosomes as the original, parent, cell. (C) Four cells, each containing
half the number of chromosomes of the original, parent, cell. (D) Two cells, each containing half
the number of chromosomes of the original, parent, cell.
Meiosis is a special type of cell
division used for making gametes. It has two separate rounds of
division that are called meiosis I and meiosis II. We have two copies of 23
chromosomes, or 46 chromosomes in total. This is the number of chromosomes
in the parent cell that begins meiosis.
Here we can see one of the
chromosomes in pink. Before meiosis begins, these 46
chromosomes are duplicated. This doesn’t change the number of
chromosomes, but the chromosome structure contains two copies of the chromosome that
we call chromatids. Then, in meiosis I, the two copies
of the 23 chromosomes are divided into two cells. So each of these cells contains 23
duplicated chromosomes. Then, in meiosis II, these two
cells containing 23 duplicated chromosomes divide a second time. This forms four cells. The duplicated chromosomes split in
these cells so each cell receives one of the two chromatids that we had seen
earlier.
Remember, these chromatids are
actually just copies of the chromosomes that were stuck together in the duplicated
chromosome structure. Once they separate in meiosis II,
we call them chromosomes. So these four cells have 23 single,
and not duplicated, chromosomes.
These are the final products of
meiosis. And this is given by answer choice
(C): four cells, each containing half the number of chromosomes of the original,
parent, cell.
