Video Transcript
What stage happens before meiosis I
but not before meiosis II? (A) Prophase, (B) cytokinesis, (C)
telophase, (D) interphase, (E) anaphase.
Meiosis is a form of cell division
that produces gametes for sexual reproduction. There are two divisions in meiosis:
meiosis I and meiosis II. We start with two copies of 23
duplicated chromosomes, or 46 in total. We’ll discuss what a duplicated
chromosome is in a moment.
During meiosis I, the two copies
are split up. So one cell gets one copy of each
of the 23 duplicated chromosomes, and the other cell gets another copy. During meiosis II, each of these
duplicated chromosomes are split into single chromosomes in another round of cell
division. This produces four cells in
total.
An essential component of this
process is the duplicated chromosomes. This allows for the correct
division of chromosomes during meiosis I and II. Before meiosis I occurs, a single
chromosome is copied, or duplicated, to form a duplicated chromosome structure, as
we see here. This happens to all the 46
chromosomes. This way, they can be split up into
the four cells during the course of meiosis I and II. This stage of duplicating a single
chromosome to form the duplicated chromosome structure takes place before meiosis
and is called interphase.
Therefore, the correct option is
given by answer choice (D), interphase.
