1. Genes are segments of that code for synthesis.
a. chromosomes; proteins
b. chromosomes; DNA
c. genes; polysaccharide
d. chromosomes; amino acids
2. What percentage of cancers are estimated to result from mutations that are not inherited?
a. less than 1%
b. 20 %
c. 5%
d. 70%
3. Which of the following does not contain condensed chromosomes that have been duplicated?
a. a cell during the G1 phase of interphase
b. a cell during prophase
c. a cell during metaphase
d. a cell immediately preceding anaphase
4. Which of the following is a good example of an allele?
a. a segment if DNA that codes for brown eyecolor
b. a section of DNA that determines eyecolor
c. a sex chromosome that determines whether you are male or female
d. a DNA sequence that produces aprotein
5. Whereas cloning is commonly used in studies of bacteria, Dolly the sheep was the only animal ever cloned.
a. True
b. False
6. If a women is homozygous dominant for a certain trait (genotype TT) and her husband is heterozygous for the trait (genotype Tt), what are the chances thattheir first child would be heterozygous? Please include the Punnett' ssquare.
a. 25%
b. 75%
c. 50%
d. 100%
7. Which of the following pairs of genotypes represent a dihybrid cross?
a. AaBBCc x aabbcc
b. AaBb x aaBB
c. Aa x aa
8. All normal human cells, except gametes, contain chromosome(s).
a. 23
b. 1
c. 46
d. over 100
9. If a women has sex-linked recessive trait, then all of her sons will have trait as well.
a. True
b. False
10. A dysfunctional gene may affect one type of cell in the body, but not othertypes, because
a. not all genes possessed by an individual are found in all cell types in thebody.
b. cells express only the genes required for their particular activities.
c. some cells are able to locate and repair defective genes.
d. some cells may not have the dysfunctional gene.
11. Each cell that enters the cell cycle contains sister chromatids
a. True
b. False
12. When two different alleles of a gene are both fully expressed in a heterozygote,but neither allele is dominant over the other, it iscalled
a. Incomplete dominance
b. codominance
c. dihybrid dominance
13. If a man with one dominant gene for Huntington's disease marries a womenwho has no genes for the disease, what is the probability that their child will have the disease?
a. 25%
b. 100%
c. 0%
d. 50%
14. What are the chances that two parents who are heterozygous dominant for two traits of interest would have a child that is dominant for one trait, but not both traits?
a. 1 in16
b. 6 in16
c. 3 in16
d. 9 in16
15. As demonstrated in SCID patients, gene therapy is now a routine and safe, means to treat genetic defects in people.
a. True
b. False
16. Brown eyes in humans are dominant to blue eyes. A brown-eyed man, whose mother was blue-eyed, marries a brown-eyed woman whose father had blue eyes. What is the probability that this couple will have a blue-eyed child?
Show your answers by drawing a Punnett's square.
17. In humans, being a tongue roller (R) is dominant over non-roller (r). A man who isa non-roller marries a woman who is heterozygous for tongue rolling.
Father'sphenotype Father'sgenotype
Mother'sphenotype Mother'sgenotype
What is the probability of this couple having a child who is a tongue roller? Show your answers by drawing a Punnett's square.
18. In guinea pigs, short hair, S, is dominant to long hair, s. Show your answers by drawing a Punnett'ssquare.
a. One guinea pig is Ss and one is ss.
Expected number of offspring:
Short hair (SS or Ss)
Long hair (ss)
b. Both guinea pigs are heterozygous for short hair. Expected number ofoffspring:
Short hair
Longhair
19. What phenotypic ratio of offspring should be expected from the cross AaBb xAAbb? Show your answers by drawing a Punnett'ssquare.
20. Lauren, who has blood type AB, marries Sal who has type B blood butwhose mother has type O.
a. List the genotypes of Lauren, Sal and Sal'smother.
b. What are the percent possibilities for the blood type of theiroffspring.