Assuming 100% reaction efficiency, how many DNA copies are created after the completion of four
complete PCR cycles? Correct Answer: 16
What is the function of DNA polymerase in the process of PCR? Correct Answer: It recognizes the
primers and uses the available dNTPs to replicate the template DNA sequence.
What are possible blood types of the parents of a patient with blood type AB? Correct Answer: A and
B
115 116 117 118 − Amino Acid Number
Tyr Gly Thr Pro − Amino Acid Sequence
TAC GGG ACA CCA − DNA Sequence
What is the amino acid in position 118 that results from a single nucleotide insertion immediately
following the three guanines that encode for glycine 116? Correct Answer: Thr
In sickle-cell disease, the glutamic acid (Glu) at position number seven is mutated to valine (Val).
What change in codons corresponds to this mutation? Correct Answer: GAA to GTA
Which type of mammalian DNA damage repair requires the presence of the chromosome that is
homologous to the damaged chromosome? Correct Answer: Recombination
Xeroderma pigmentosum (XP) is a recessive genetic disease that occurs when one or more of the
genes that perform nucleotide excision repair are nonfunctional.
Why do XP patients have a much higher incidence of skin cancer than the general population?
Correct Answer: The mutation rate of all other genes is higher due to failure to repair.
Which mRNA sequence results in a polypeptide that contains three amino acids? Correct Answer: 5' -
CUU GAU ACU UAG - 3'
Which template strand DNA sequence would result in the amino acid (Ser)? Correct Answer: 5' -
CGA - 3'
What is the complementary sequence for the following DNA sequence?
5' - GCC ATC TCG AAT - 3' Correct Answer: 5' - ATT CGA GAT GGC - 3'
Studies have shown that increased expression of two genes called SIRT1 and SIRT2 is associated
with chronic exposure to cocaine and contributes to drug addiction.
What difference in the regions of the SIRT1 and SIRT2 genes in people addicted to cocaine
increases their expression? Correct Answer: The nucleosomes become more widely spaced.