MCB 250 Exam 3 ACTUAL QUESTIONS
AND CORRECT ANSWERS
Homologous recombination involves all of the following except ______.
A. a double stranded break in the DNA
B. formation of a heteroduplex sequence
C. two nearly identical DNA sequences
D. alignment of DNA on different chromosomes
E. addition of Uracil into the DNA - CORRECT ANSWER E. addition of Uracil into the DNA
In homologous recombination, the term "patch product" refers to _____.
A. a localized change in DNA sequence resulting from DNA mismatch repair.
B.the junction site of chromosomal crossing over.
C. the product of any Holliday junction resolution.
D. short stretches of DNA cut out by the Uvr system.
E. a region of partially newly synthesized DNA flanked on either side by sequences that have not
experienced re-assortment - CORRECT ANSWER E. a region of partially newly synthesized
DNA flanked on either side by sequences that have not experienced re-assortment
In E. coli, which protein is central to the process of strand invasion?
A. RecD
B. RecA
C. RecC
D. RecUV
E. RecB - CORRECT ANSWER B. RecA
The biggest difference between homologous recombination and non-homologous end joining is:
A. The need to process the ends of the DNA
B. The ability to restore the DNA to its original sequence
C. The need to ligate the strands to complete the repair
, D. Non-homologous end joining is found only in bacteria - CORRECT ANSWER B. The
ability to restore the DNA to its original sequence
CRISPR can be used to edit a eukaryotic chromosome. It can be used to mutate a wild type sequence
or repair a defect back to wildtype. In order to carry out repair, in addition to the CRISPR proteins and
guide RNA, one needs to add which of following to the cells?
A. Ligase
B. RecA protein
C. Mediator
D. DNA with the wild type sequence - CORRECT ANSWER D. DNA with the wild type
sequence
In a monohybrid cross, what is the probability of seeing the recessive phenotype in the F2 progeny?
A. 3/4
B. 1/4
C. 2/3
D. 1/3 - CORRECT ANSWER B. 1/4
Why do alleles of genes on the same chromosome sort independently during meiosis?
A. Sister chromatid separation during mitosis
B. Sister chromatid separation during meiosis
C. Homologous recombination during meiosis
D. Homologous recombination during mitosis - CORRECT ANSWER C. Homologous
recombination during meiosis
In the genetic screen we discussed, which generation might contain homozygous mutant animals?
A. P
B. F2
C. F1
D. F3 - CORRECT ANSWER D. F3
What structure is the Pax6 gene important for during mammalian development?
AND CORRECT ANSWERS
Homologous recombination involves all of the following except ______.
A. a double stranded break in the DNA
B. formation of a heteroduplex sequence
C. two nearly identical DNA sequences
D. alignment of DNA on different chromosomes
E. addition of Uracil into the DNA - CORRECT ANSWER E. addition of Uracil into the DNA
In homologous recombination, the term "patch product" refers to _____.
A. a localized change in DNA sequence resulting from DNA mismatch repair.
B.the junction site of chromosomal crossing over.
C. the product of any Holliday junction resolution.
D. short stretches of DNA cut out by the Uvr system.
E. a region of partially newly synthesized DNA flanked on either side by sequences that have not
experienced re-assortment - CORRECT ANSWER E. a region of partially newly synthesized
DNA flanked on either side by sequences that have not experienced re-assortment
In E. coli, which protein is central to the process of strand invasion?
A. RecD
B. RecA
C. RecC
D. RecUV
E. RecB - CORRECT ANSWER B. RecA
The biggest difference between homologous recombination and non-homologous end joining is:
A. The need to process the ends of the DNA
B. The ability to restore the DNA to its original sequence
C. The need to ligate the strands to complete the repair
, D. Non-homologous end joining is found only in bacteria - CORRECT ANSWER B. The
ability to restore the DNA to its original sequence
CRISPR can be used to edit a eukaryotic chromosome. It can be used to mutate a wild type sequence
or repair a defect back to wildtype. In order to carry out repair, in addition to the CRISPR proteins and
guide RNA, one needs to add which of following to the cells?
A. Ligase
B. RecA protein
C. Mediator
D. DNA with the wild type sequence - CORRECT ANSWER D. DNA with the wild type
sequence
In a monohybrid cross, what is the probability of seeing the recessive phenotype in the F2 progeny?
A. 3/4
B. 1/4
C. 2/3
D. 1/3 - CORRECT ANSWER B. 1/4
Why do alleles of genes on the same chromosome sort independently during meiosis?
A. Sister chromatid separation during mitosis
B. Sister chromatid separation during meiosis
C. Homologous recombination during meiosis
D. Homologous recombination during mitosis - CORRECT ANSWER C. Homologous
recombination during meiosis
In the genetic screen we discussed, which generation might contain homozygous mutant animals?
A. P
B. F2
C. F1
D. F3 - CORRECT ANSWER D. F3
What structure is the Pax6 gene important for during mammalian development?
