Video Transcript
Which of the following best defines
genetic engineering? (A) Genetic engineering is the
repeated breeding of organisms with desired characteristics. (B) Genetic engineering is the
modification of the DNA of an organism. (C) Genetic engineering is the
modification of the physical characteristics of an organism. (D) Genetic engineering is a form
of cloning. (E) Genetic engineering is the
creation of new animals.
Key knowledge required to answer
this question is a basic understanding of genetic engineering. So let’s take a look at an example
of this technique. Have you ever had to go to the
doctor to get a vaccination and they take out a great big needle? Well, it’s possible that maybe
someday we’ll be getting vaccines from bananas. Vaccines are an important tool to
prevent disease, but they often come with a painful shot. Would you like it if you went to
the doctor and they said, for your vaccination this year, you just have to eat this
banana?
Genetic engineers have been working
on making edible vaccines, and this is the basic gist of what they’re doing. They need to start with something
edible, like a banana, and the pathogen, which is the disease-causing agent. And they have little proteins on
them that our immune system can recognize to attack, and those little proteins are
called antigens. After locating the gene that codes
for the antigen and the genetic material of the pathogen, this gene is isolated from
the rest of the pathogens’ DNA, and it’s inserted into the DNA of the banana. But since bananas are just part of
a banana tree and banana trees have many, many cells that contain DNA, this process
is just performed on a few banana tree cells. Then the cells are cultured and
grown.
Now the bananas will have the
antigen from the pathogen grown in them. And the idea is if you eat enough
of the antigen, your immune system can recognize it and get all ready in case the
real virus or bacterium or other kind of pathogen shows up. So this banana, like all
genetically engineered organisms, contains DNA from more than one kind of
organism. So that’s what genetic engineering
is.
And it’s time to look at our
solution options, starting with (A), genetic engineering is the repeated breeding of
organisms with desired characteristics. But that’s selective breeding and
humans have been doing that for thousands of years. It’s not really considered genetic
engineering. Option (B) says, the genetic
engineering is the modification of the DNA of an organism. And that’s exactly what happened in
our example. So this one sounds really good. Option (C) says, the genetic
engineering is the modification of the physical characteristics of an organism. Well, genetic engineering does
modify physical characteristics of an organism, but not directly. You have to modify the DNA to
result in a change in physical characteristics. So option (C) is not correct.
Option (D) says that genetic
engineering is a form of cloning. Well, cloning is really a part of
the process in genetic engineering. After you have the cell genetically
modified the way you want it, you clone it or make lots of identical cells. So option (D) is not correct. Option (E) says that genetic
engineering is the creation of new animals. But genetic engineering is really
about moving a gene of interest from one species to another species. So option (E) is not correct. Therefore, the answer to the
question, which of the following best defines genetic engineering, is genetic
engineering is the modification of the DNA of an organism.
