Video Transcript
Fill in the blank. The stage that occurs before cell
division when the DNA in the cell doubles is called blank. Option (A), prophase; option (B),
metaphase; option (C), anaphase; option (D), telophase; or option (E),
interphase.
This question mentions the process
of cell division. You may recall that the process by
which a single cell divides to form two new identical cells is called mitosis. So why is mitosis important? Think about a plant that starts out
as a seed and grows out of the ground into a plant. This growth is possible because the
cells divide. Mitosis is a crucial part of growth
in all multicellular organisms. Mitosis itself is divided into four
stages, prophase, metaphase, anaphase, and telophase. You can see these four stages
listed in our answer choices. Over the course of these four
stages, the DNA contained in the original cell is split into two so that each of the
new daughter cells receives its own DNA.
Let’s stop and think for a
moment. If the DNA in the original cell is
split between the two daughter cells, wouldn’t this mean that each daughter cell
only gets half? Well, dividing cells fixed this
issue by making a copy of their DNA before mitosis actually begins. Through the stages of mitosis, the
two copies of DNA are separated and are divided equally between the two daughter
cells. In this way, each new cell receives
an entire copy of the original DNA.
So when does this DNA copying
occur? Mitosis is actually only a small
part of a larger process called the cell cycle. During a stage called interphase,
which occurs before mitosis, the DNA of the cell is copied in preparation for cell
division. With this in mind, we are able to
fill in the blank to the following question: The stage that occurs before cell
division when the DNA in the cell doubles is called blank. The correct answer here is (E),
interphase.