Video Transcript
What is the difference between
genes and DNA? (A) A gene is a single strand of
DNA, while DNA is a functional part of the nucleotide. (B) A gene is a functional part of
DNA, while DNA is a long chain of nucleotides. (C) A gene is a single strand of
RNA, while DNA is a functional part of the gene. (D) A gene is a long chain of RNA,
while DNA is a functional part of the gene.
Our genetic information is stored
in the nucleus of our cells as DNA. We have a lot of DNA. And if we were to line up all the
DNA in a single cell, there would be about two meters of it. This is not one long, continuous
molecule of DNA. Instead, it’s actually organized
into 46 linear molecules of DNA called chromosomes. Each chromosome is a highly
compacted form of DNA. Let’s look more closely at how DNA
is packaged in a chromosome.
If we unravel a chromosome, we can
see that DNA is wound up tightly around special proteins called histones. DNA is really just a long sequence
of subunits called nucleotides. We can see one of these nucleotides
circled here in pink. These different colored bands
between the two DNA strands represent the different nitrogenous bases of the
nucleotides.
In DNA, there are four kinds of
nitrogenous bases: guanine, represented in orange; cytosine, represented in blue;
adenine, represented in green; and thymine, represented in pink. The sequence of these nitrogenous
bases in these nucleotides can provide instructions for different functional units,
like a protein, such as insulin. We call these functional parts of
DNA genes.
So now we can answer our
question. The statement that correctly
differentiates a gene and DNA is given by answer choice (B). A gene is a functional part of DNA,
while DNA is a long chain of nucleotides.
