Video Transcript
Neurons do not contain
centrioles. What biological process does this
prevent neurons from carrying out? (A) Aerobic respiration, (B)
anaerobic respiration, (C) apoptosis, (D) cell signaling, (E) mitosis.
This question provides us with a
statement: neurons do not contain centrioles. So in order to correctly answer
this question, we need to recall the function of centrioles in the cell.
Let’s think back to our lessons on
mitosis, which is the process of cellular division and replication. Centrioles are very important to
these processes because they produce spindle fibers and microtubules. These structures first appear in
the prophase of mitosis. And they’re responsible for
connecting to the centromere of each duplicated chromosome. Then, during anaphase, they aid in
pulling apart the duplicated chromosomes to the opposite poles of the cell. Therefore, centrioles are
absolutely necessary for the process of mitosis. This means in the absence of
centrioles, neurons cannot divide and renew themselves.
This is an interesting fact about
neurons that has important implications. After about the age of 18 months in
humans, neurons get specialized and stop dividing. This means, in contrast to most of
our body tissue that are able to heal perfectly in the case of an injury or
disorder, injured neurons will not be replaced.
So to review, without centrioles,
neurons are unable to undergo the process of mitosis and replace injured
neurons. With this information, we are now
ready to answer the question. Therefore, the biological process
that is prevented in neurons due to the lack of centrioles is mitosis.
