____________________________
Modern Genetics Review
____________________________
____Modern Genetics Review____
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
____
____
____
____
____
____
____
____
____________________________
_
1. Which of these traits is controlled by a gene with multiple alleles?
a. straight hairline
b. smile dimples
c. widow’s peak
d. blood type
2. Why does height in humans have such a wide variety of phenotypes?
a. Height is controlled by at least four genes.
b. The gene for height has only two alleles.
c. Height is controlled by sex-linked genes.
d. Height is controlled by a recessive allele.
3. What controls variations in skin color among humans?
a. a person’s diet
b. many genes
c. multiple alleles of a single gene
d. two alleles of a single gene
4. Which of these human traits is altered by variations in environment?
a. hairline
b. height
c. smile dimples
d. blood type
5. What is a pedigree?
a. a chart that tracks which members of a family have a particular trait
b. a geneticist who studies the inheritance of traits in humans
c. a picture of all of the chromosomes in a cell
d. an allele passed from parent to child on a sex chromosome
6. What would be the best way to predict the probability of a baby having cystic fibrosis?
a. by studying the parents’ karyotypes
b. by studying the family’s pedigree chart
c. by exploring new methods of genetic engineering
d. by determining whether the parents have codominant alleles
7. What is the purpose of the Human Genome Project?
a. to identify the DNA sequence of every gene in the human genome
b. to clone every gene on a single chromosome in human DNA
c. to cure genetic diseases
d. to inbreed the best genes on every chromosome in human DNA
8. Both parents of a child have type A blood. What might their child’s blood type be?
a. Type A only
b. Type A or type B
c. Type A or type O
d. Type A or type AB
9. Sex-linked genes are genes on
a. the X chromosome only.
b. the Y chromosome only.
c. the X and Y chromosomes.
d. all 23 pairs of chromosomes.
____ 10. Which form of selective breeding crosses parents with the same or similar sets of alleles?
a. fertilization
b. inbreeding
c. hybridization
d. cloning
____ 11. Hemophilia is caused by a(n)
a. recessive allele on the X chromosome.
b. extra chromosome.
c. dominant allele.
d. codominant allele.
____ 12. Many characteristics are affected by interactions between genes and
a. chromosomes.
b. the environment.
c. alleles.
d. carriers.
____ 13. Adults with Down syndrome can often find work because they have received
a. folic acid.
b. physical therapy.
c. education and job training.
d. genetic counseling.
14. What do the squares represent on the pedigree? _______________________________________________________
_____________________________________________________________________________________________
15. Which pairs of individuals in the pedigree have children? _______________________________________________
16. Which individuals neither have the trait nor are carriers? ________________________________________________
17. Could the trait that is traced by this pedigree be sex-linked? Explain why or why not. _________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
Completion
Complete each statement.
18. Except for ______________________________, all people have different DNA.
19. The three alleles on the single gene that controls blood type are said to be ___________________________.
20. When many genes control a trait, the trait will show a large number of ______________________________.
21. A carrier is a person who has one ____________________________________ allele for a trait.
22. A(n) ___________________________________ is used to track the occurrence of a trait in a family.
23. People who have the genetic disorder called ____________________________________ suffer from abnormally low
levels of oxygen in the blood.
24. A person who has the genetic disorder called __________________________________ bleeds easily.
25. ____________________________________________ is caused by the presence of an extra chromosome.
26. Breeders use a technique called ___________________________ to cross genetically different individuals.
27. A gene from one organism is inserted into the DNA of another organism in the process known as
___________________________________________________.
28. Scientists in the Human Genome Project are working to identify the _______________________________ of every
human gene.
29. All of the DNA in one cell of an organism is called a(n) _______________________________________.
30. A selective breeding technique called _____________________________________ has been used to breed purebred
racehorses.
31. A pattern produced from fragments of the DNA of a specific person is called a(n)
____________________________________________.
32. A karyotype can be used to determine the number of _____________________________ in a person’s cells.
Create a Pedigree
Draw a pedigree using the following information. Be sure to create an appropriate key.
33. Jane and Joe are the first generation in the pedigree. Jane is a carrier of sickle-cell disease. They have two boys,
Scott and Ryan. Ryan is not a carrier and does not have any offspring. Scott is a carrier of sickle-cell disease and
marries Heather who is also a carrier. They have four children. Sara and Jim are carriers of sickle-cell disease and
Megan and George have sickle-cell disease. (Be sure to label the pedigree.)
Essay
Fully answer all of the following questions with detailed explanation. Minimum of four well developed complete
sentences.
34. Human eyes come in a variety of colors ranging from light blue to very dark brown. Explain why eye color is not
likely to be controlled by a single gene.
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
35. Explain what causes cystic fibrosis and describe its effects on the body. What are some treatments for those with the
disease?
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
36. A plant breeder clones a plant with beautiful flowers. Define cloning and explain how the cloned offspring compare
to the parent plant.
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
37. Contrast hybridization and inbreeding.
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________