Name: ______
Honor Pledge:
Chapter 14 Human Genetics
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
____ 1. Because the X chromosome contains genes that are vital for normal development, no baby has been born
a. / without an X chromosome. / c. / with three X chromosomes.b. / with four X chromosomes. / d. / with one X chromosome.
____ 2. Which of the following genotypes result in the same phenotype?
a. / IBi and ii / c. / IBIB and IAIBb. / IBIB and IBi / d. / IAIA and IAIB
____ 3. The process of DNA fingerprinting is based on the fact that
a. / most people have DNA that contains repeats.b. / the most important genes are different among most people.
c. / no two people, except identical twins, have exactly the same DNA.
d. / most genes are dominant.
____ 4. The human genome was sequenced
a. / using DNA fingerprinting.b. / by looking for overlapping regions between sequenced DNA fragments.
c. / by sequencing each gene on each chromosome, one at a time.
d. / using open reading frames.
____ 5. A change in a single gene causes the protein called CFTR to
a. / become less soluble.b. / destroy the cell membrane.
c. / transport sodium ions instead of chloride ions.
d. / fold improperly.
____ 6. What is the approximate probability that a human offspring will be female?
a. / 75 percent / c. / 25 percentb. / 10 percent / d. / 50 percent
____ 7. A Barr body is
a. / an activated X chromosome.b. / a condensed X chromosome that is inactive.
c. / an activated Y chromosome.
d. / a condensed Y chromosome that is inactive.
____ 8. Which of the following combinations of sex chromosomes represents a female?
a. / XX / c. / XXXYb. / XY / d. / XXY
____ 9. Colorblindness is more common in males than in females because
a. / the allele for colorblindness is located on the Y chromosome.b. / males who are colorblind have two copies of the allele for colorblindness.
c. / the allele for colorblindness is recessive and located on the X chromosome.
d. / fathers pass the allele for colorblindness to their sons only.
____ 10. Which of the following are shown in a karyotype?
a. / sex chromosomes / c. / autosomesb. / homologous chromosomes / d. / all of the above
____ 11. Which of the following is the first step in gene therapy?
a. / allowing recombinant viruses to infect human cellsb. / identifying the faulty gene that causes the disease
c. / using restriction enzymes to cut out the normal gene from DNA
d. / splicing the normal gene to viral DNA
____ 12. A pedigree CANNOT be used to
a. / determine whether an allele is dominant or recessive.b. / show how a trait is passed from one generation to the next.
c. / determine whether a trait is inherited.
d. / none of the above
____ 13. A calico cat will be ______for the gene that codes for coat spot color.
a. / heterozygous / c. / homozygousb. / codominant / d. / incomplete dominance
____ 14. What is the probability that a human sperm cell will carry an X chromosome?
a. / 25 percent / c. / 50 percentb. / 100 percent / d. / 0 percent
Completion
Complete each sentence or statement.
15. A(An) ______can be used to determine whether a person has inherited the normal number of chromosomes.
16. People who have sickle cell disease inherited ______copy(ies) of the sickle cell allele.
17. In people with Down Syndrom, aquiring an extra copy of chromosome 21 in a gamete is achived through this process during meiosis: ______
18. A boy who has hemophilia inherited the disorder from his ______.
19. The alleles IA and ______for the ABO blood group are NOT codominant.
Short Answer
20. Why is a person who has Klinefelter’s syndrome (XXY) a male even though he has two X chromosomes in his cells?
21. A man who does not have hemophilia and a woman who is a carrier of the disorder have a son. What is the probability that their son has hemophilia?
22. Give two reasons why it is almost impossible to associate many human traits with single genes.
23. Why are viruses used in gene therapy?
Essay
24. Contrast the abnormal hemoglobin found in a person who has sickle cell disease with normal hemoglobin. How does this difference affect the person’s red blood cells?
Other
USING SCIENCE SKILLS
The pedigree shows the inheritance of free earlobes and attached earlobes in five generations of a family. Attached earlobes is caused by a recessive allele (f).
Figure 14–1
25. Predicting Predict the genotype and phenotype of individual 14 in Figure 14-1.
26. Inferring In Figure 14-1, are any of the descendents of individuals 1 and 2 homozygous for free earlobes? Explain your answer.
27. Interpreting Graphics In Figure 14-1, how many children of individuals 4 and 5 have attached earlobes?
28. Inferring Can you be certain of the genotype of individual 5 in Figure 14-1? Explain.
29. Inferring Is individual 2 in Figure 14-1 homozygous or heterozygous for free earlobes? Explain.