Video Transcript
Read this passage on DNA and
genes. DNA, deoxyribonucleic acid, is the
genetic material found in our cells. DNA is made up of two strands that
twist around each other to form a double helix. A gene is a section of blank that
contains the instructions to produce a certain characteristic. Genes work in pairs and come in
different versions. One version of a gene can be
dominant over another. What should replace the gap?
Almost every single cell in a
human’s body contains DNA, packed up in chromosomes to fit into the cell’s
nucleus. DNA, or deoxyribonucleic acid, is
the genetic component containing all of the information that an organism needs to
exist. It is made up of two strands that
form a double helix. These strands are made up of chains
of nucleotide bases: adenine, guanine, thymine, and cytosine. Almost every single cell in the
human body contains more than 6.2 billion base pairs.
A gene is a specific sequence of
DNA. And it contains instructions that
can directly code for or at least influence certain characteristics, such as hair
color, eye color, height, and many other traits. There are different versions of
genes called alleles. This helps to explain, for example,
why some people have blue eyes while others have brown eyes. We inherit two alleles for every
genetic trait, one from each of our biological parents. Some of these alleles can be
dominant over the other. This means that if a dominant
allele is inherited from one of your biological parents and is therefore present in
your genotype or genetic makeup, the dominant trait it codes for will always be
expressed. As a gene is a section of DNA, we
know that this is the correct answer to our question.
So, the word that should fill in
the blank in the passage on DNA and genes is DNA.
