Download Karyotypes

Biology
Name___________________
Date__________Hour______
Karyotypes
All living organisms store their genetic instruction manual in molecules of DNA. Although the specific
sequence of bases may differ from species to species, the structure of DNA is consistent among all living
organisms. The DNA is arranged in long molecules that are called chromosomes. Your chromosomes
are stored in the nucleus of each of your cells. A gene is a region on a chromosome that provides the
instructions to make a particular protein. Proteins control all the reactions and physical characteristics of
your body.
A karyotype is a picture of the chromosomes that reside inside the nucleus of each of your cells. On
a karyotype each chromosome is paired with a matching chromosome. These two matching
chromosomes are called homologous chromosomes. Homologous chromosomes provide the
instructions for the proteins that control the same traits. One chromosome of a homologous pair comes
from your mom and the other from your dad.
Directions: Use the karyotypes on the back of this paper to answer the following questions.
1. Put a star next to the karyotype that matches your sex.
2. Circle one pair of chromosomes that are homologous chromosomes on the karyotype that
matches your sex.
3. A chromosome is one molecule of _______________.
4. Using the karyotype count the total number of chromosomes in each of your cells. _________
5. Notice the chromosomes are arranged in pairs. Pick two colors. Color one pair of the
chromosomes pink and the other member of the pair green.
6. The ____________ colored chromosomes are copies of DNA that came from your __________.
The ____________ colored chromosomes are copies of DNA that came from your __________.
7. What is the total number of pairs of homologous chromosomes in each cell? __________
8. Look at the chromosome pair number 23 for the male and female karyotypes. What is different
about the 23rd pair of chromosomes in males and females?
9. Females have two __________ chromosomes numbered 23.
Males have one _______ and one _______ chromosomes numbered 23.
10. What is different about the karyotype below?