Name________________________________
Review of the Genetics Unit
1. What is a trait? ______________________________________________________________________
2. What is an example of a trait? _____________________________________________________
Word bank: gene
chromosome
DNA
allele
3. There are 23 pairs of _________________________ in the human body, which look like x’s
and are made up of ______________________. These are spiral- ladder like structures and
have many _____________________ on them that tell what kind of traits that person will
have. Different forms of those are called ___________________, and for every trait there
are two of these: one from the mother and one from the father.
3. What does genotype mean?_________________________________________________________
4. What is an example of a genotype? ________________________________________________
5. What does phenotype mean? _______________________________________________________
6. What is an example of phenotype? _________________________________________________
7. What does heterozygous mean? ___________________________________________________
8. What is an example of heterozygous genes? ______________________________________
9. What does homozygous mean? _____________________________________________________
10. What is an example of homozygous genes? ______________________________________
11. What does it mean when a trait is dominant?
____________________________________________________________________________________________
12. What does it mean when a trait is recessive?
____________________________________________________________________________________________
13. The dominant trait for flower color is purple, and the recessive trait is white.
Use P=purple flowers and p=white flowers.
Please cross two heterozygous parents.
-What percent of the offspring are purple?
-What percent of the offspring are white?
14. Please cross a homozygous dominant parent with a homozygous recessive
parent.
What percent of the offspring are purple?
What percent of the offspring are white?
15. The Grey color of mice is dominant to a white color. Please use G=grey and
g=white
Please cross two homozygous recessive parents:
-What percent of the offspring are grey?
-What percent of the offspring are white?
Please cross a homozygous dominant parent with a heterozygous recessive
parent.
Which two of these offspring could be bred to produce some white mice?
How do you know?