Question 1

Which of the following best describes the role of the lac operon in prokaryotic gene regulation?

Accepted Answer

It is an inducible system that metabolizes lactose into glucose for energy.

Question 2

In the trp operon, what is the function of tryptophan as a corepressor?

Accepted Answer

Tryptophan binds to the repressor, enabling it to bind to the operator and suppress transcription.

Question 3

Which of the following is a mechanism unique to eukaryotic gene regulation and not found in prokaryotes?

Accepted Answer

Alternative splicing of pre-mRNA

Question 4

A mutation changes a purine to another purine. What type of mutation is this?

Accepted Answer

Transition

Question 5

Which DNA repair mechanism is most likely to fix a thymine dimer caused by UV light?

Accepted Answer

Direct repair

Question 6

In eukaryotic cells, methylation of cytosine in CpG islands typically results in:

Accepted Answer

Transcriptional silencing

Question 7

Which of the following best explains why the Ames test is used in genetics research?

Accepted Answer

To determine if a chemical induces mutations by detecting reversion mutations

Question 8

A patient is diagnosed with Huntington’s disease, which is caused by copy number variation. Which type of mutation is most likely responsible?

Accepted Answer

Expansion of a trinucleotide repeat

Question 9

During meiosis I, homologous chromosomes pair and exchange genetic material. Which structure facilitates this process?

Accepted Answer

Synaptonemal complex

Question 10

Which of the following is a post-transcriptional regulatory mechanism in eukaryotes?

Accepted Answer

Alternative splicing

Question 11

A mutation occurs in a somatic cell and is repaired before replication. What is the likely outcome?

Accepted Answer

The mutation is not passed to daughter cells.

Question 12

Which equation best represents the reduction division in meiosis I?

Accepted Answer

$$2N \rightarrow N$$

Question 13

Which protein is directly involved in the condensation of metaphase chromosomes?

Accepted Answer

SMC proteins (condensin)

Question 14

In prokaryotic conjugation, what is the role of the F factor?

Accepted Answer

It enables the donor cell to transfer genetic material to the recipient cell.

Question 15

Which of the following best describes the function of miRNA in eukaryotic cells?

Accepted Answer

It blocks translation of target mRNA.

Question 16

A base addition mutation occurs in a coding region. Which type of mutation is most likely to result?

Accepted Answer

Frameshift mutation

Question 17

Which step is NOT part of the general DNA repair process?

Accepted Answer

Translation of the repaired DNA

Question 18

Which of the following scenarios best illustrates attenuation in the trp operon?

Accepted Answer

Transcription is terminated early due to high tryptophan levels, preventing expression of biosynthetic genes.

Question 19

Which of the following is a plausible outcome of homologous recombination during transformation in bacteria?

Accepted Answer

The incorporated DNA fragment replaces a nearly identical region in the recipient genome.

Question 20

Which histone proteins form the core octamer of a nucleosome?

Accepted Answer

H2A, H2B, H3, and H4 (two of each)

Gene Regulation, Mutation, Genetic Transfer, and Chromosome Structure: Study Notes for General Genetics

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