AP-Micro Microbiology: Microbial Genetics 2

Question 1

Which type of RNA serves as the template for reverse transcriptase in retroviruses?

Accepted Answer

mRNA

Answer

Retroviruses carry single-stranded mRNA genomes that reverse transcriptase uses as a template to synthesize complementary DNA.

Question 2

In bacterial conjugation, the F factor can integrate into the host chromosome, forming what type of cell?

Accepted Answer

Hfr cell

Answer

When the F factor integrates into the bacterial chromosome, it creates an Hfr (high-frequency recombination) cell capable of transferring chromosomal genes at elevated rates.

Question 3

A frameshift mutation is most likely caused by which of the following?

Accepted Answer

Insertion of two nucleotides

Answer

Frameshift mutations result from insertions or deletions that are not multiples of three, shifting the reading frame; insertion of two nucleotides disrupts the triplet codons downstream.

Question 4

Which enzyme is responsible for removing RNA primers during DNA replication in bacteria?

Accepted Answer

DNA polymerase I

Answer

DNA polymerase I removes RNA primers using its 5'→3' exonuclease activity and fills in the resulting gaps with DNA.

Question 5

In Lederberg and Tatum's experiment demonstrating bacterial recombination, auxotrophic strains were used. What is an auxotroph?

Accepted Answer

An organism that requires an external supply of a specific nutrient

Answer

An auxotroph has lost the ability to synthesize a specific nutrient and must obtain it from the environment to grow.

AP Practice Test

AP Practice Test

AP-Micro Microbiology: Microbial Genetics 2