Video Transcript
The stages of the first meiotic
division are listed below: prophase I, metaphase I, anaphase I, telophase I. In which stage do the spindle
fibers move the chromosomes to opposite ends of the cell? (A) Prophase I, (B) metaphase I,
(C) anaphase I, (D) telophase I.
Meiosis is a special form of cell
division that produces gametes for sexual reproduction. There are two separate divisions in
meiosis called meiosis I and meiosis II. We start with two copies of 23
chromosomes, or 46 in total. Before meiosis, these 46
chromosomes are copied, or duplicated, to form a duplicated chromosome
structure. This happens during interphase. After this stage, meiosis I can
begin. Let’s go over the steps of meiosis
I to answer this question.
Here’s the parent cell that we’ll
be following during meiosis I. Notice that there’s four
chromosomes in the nucleus, but in real life, there’s 46 chromosomes. There’s two copies of these
chromosomes, and we’re showing one copy in pink and the other in blue. The first stage of meiosis I is
called prophase I. Here, the spindle fibers begin to
form and the nuclear membrane breaks down. Then, in metaphase I, the
duplicated chromosomes line up along the equator of the cell. In anaphase I, the duplicated
chromosomes are separated to opposite ends of the cell by the spindle fibers.
Then, in telophase I, the nuclear
membrane reforms around the separated chromosomes and the cells divide. Each cell has 23 duplicated
chromosomes that we can see in the upper diagram and the lower diagram. Then, in meiosis II, these
duplicated chromosomes separate into single chromosomes to form four cells.
Now that we’ve seen the different
stages of meiosis, we can answer our question. The stage where the spindle fibers
move the chromosomes to opposite ends of the cell is given by answer choice (C),
anaphase I.
