A student is asked to describe
themselves. They write “I have blue eyes and
naturally brown hair. When I was younger, I tripped over
and hurt myself, and now I have a scar on my arm.” Which of the characteristics
described above did this student not inherit from their parents? (A) Blue eyes, (B) brown hair, (C)
blue eyes and brown hair, or (D) the scar on their arm.
DNA is a very long molecule that
stores our genetic information. DNA has different sections that
give instructions for different characteristics, like the color of our eyes or how
tall we are. We call these genes, and different
genes can give different characteristics.
Humans reproduce by sexual
reproduction. This is where the male sperm cell,
which contains his DNA, fertilizes the female’s egg cell, which contains her
DNA. This makes an embryo; that’s a
combination of both their DNA. This embryo can then develop into a
baby and grow up. This child can only inherit the
genes that their parents had. In this example, blue eyes and
brown hair are both inherited genetic traits.
If we look back at the question,
the scar on the student is a characteristic that they developed due to something
that happened after they were born. This scar wasn’t given to the child
by their parents’ DNA. Therefore, this is not an inherited
trait. So the correct answer is (D) the
scar on their arm.