Name:___________________________________________________ Date:____________________ Pd:______
Heredity (Chapter 5) Study Guide
Part I: Vocabulary. Using the word bank below, match each word to its correct definition.
alleles
dominant
genetic engineering
recombinant DNA
genetics
genotype
heredity
heterozygous
homozygous
incomplete dominance
phenotype
polygenic inheritance
Punnett square
recessive
sex-linked gene
Gregor Mendel
1. The allele for hemophilia is on the X chromosome and is considered a ___________________________.
2. ______________________________ is the passing of traits from one generation to another.
3. The different forms a gene may have for a trait are called _____________________________.
4. In ______________________________ both alleles are expressed in offspring.
5. ______________________________ is known as “The Father of Genetics”.
6. A ______________________________ trait covers up other traits.
7. In a Punnett square, a small letter (t) stands for a ______________________________ allele.
8. A tool used to predict the possible offspring of a mating is called a ______________________________.
9. The genetic makeup of an organism is called its ______________________________.
10. ______________________________ is the way an organism looks and behaves a result of its genotype.
11. The study of how traits are inherited through the interactions of alleles is
______________________________.
12. Through ______________________________ scientists are experimenting to change the arrangement of
DNA in a gene.
13. An organism with two alleles that are exactly the same is _____________________________.
14. ______________________________ occurs when a group of gene pairs acts together to produce a single
trait (Examples include height and skin color).
15. An organism that has two different alleles for a trait is ______________________________.
16. A type of genetic engineering where a useful gene is inserted into a bacterium is known as
__________________________________________.
Part II: Punnett Square Practice Problems. For each problem below you must write down your “cross” and a
punnett square. Box or circle the final answer.
17. In silkworms, the dominant allele for cocoon color is yellow (Y), and the recessive allele is white cocoon (y).
If white cocoon silk worm is crossed with a homozygous dominant yellow cocoon silk worm, what will be all
the possible genotypes and phenotypes of the offspring?
18. In mice, the dominant allele for eye color is black (B), and the recessive allele is red eyes (b). If two
heterozygous parents are crossed, what will be the probability of the offspring having red eyes?
19. A widow’s peak (W) hairline is dominant to straight hairline (w). A straight hairline person is crossed with
another person who is heterozygous for the trait. What is the probability of the offspring having a widow’s
peak?
20. Sex-Linked Punnett Square. Colorblindness is inherited as a sex-linked recessive disease. An affected male
marries a heterozygous female. Use b for color blindness, and use B for normal.
What is the genotype of the male (remember you put the genes on top of the X chromosome): ____________
What is the genotype of the female: ________________
Draw and complete the punnett square below:
What is the probability that the daughters will be color blind? _____________________
What is the probability that the sons will be color blind? ______________________
Part III: Short Answer. Respond to each question/prompt completely in the space provided.
21. The pedigree below shows how color-blindness (a sex-linked disorder) is spread through this family. Use
this pedigree to answer the questions.
a. How many individuals in the pedigree are affected with color blindness? ____________________________
b. How many individuals in the pedigree are male? _________________________________
c. How many individuals in the pedigree are female? ______________________________
d. How many females are affected with color blindness?________________________________
e. All of the carriers are which sex? Why is that the case?
__________________________________________________________________________________________
__________________________________________________________________________________________
22. How is incomplete dominance different from the patterns observed by Mendel?
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
23. Genetic counselors help individuals determine the risk of passing a disease on to their offspring. What
would a pedigree be a useful tool for a genetic counselor?
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
24. Do you agree with genetic testing for diseases? Use specific evidence from class discussions, the video, or
class readings to support your answer.
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________