Question 1

Which codon signals the start of translation in eukaryotic cells?

Accepted Answer

AUG

Question 2

A mutation changes the DNA sequence from $$5'	ext{AGG}ightarrow 5'	ext{AGA} in a $$coding region. What type of mutation is this?

Accepted Answer

Silent mutation

Question 3

If a DNA sequence $$5'	ext{ATG GCT TAA} is $$transcribed and translated, what is the resulting amino acid sequence?

Accepted Answer

Met-Ala-Stop

Question 4

Which process removes introns from pre-mRNA before it leaves the nucleus?

Accepted Answer

Splicing

Question 5

A patient is exposed to UV light, resulting in the formation of thymine dimers. What is the most likely consequence if these dimers are not repaired?

Accepted Answer

Disruption of DNA replication leading to mutations

Question 6

Which of the following best describes a frameshift mutation?

Accepted Answer

A mutation that inserts or deletes a nucleotide, altering the reading frame

Question 7

What is the function of exons in a gene?

Accepted Answer

They code for the final protein product

Question 8

Which enzyme is responsible for synthesizing RNA from a DNA template during transcription?

Accepted Answer

RNA polymerase

Question 9

A mutation changes the codon $$5'	ext{UAC} to$$ $$5'	ext{UAA}. $$What is the effect on the protein?

Accepted Answer

Premature termination of translation

Question 10

Which of the following is NOT a reason why mRNA must be processed before leaving the nucleus?

Accepted Answer

To remove exons

Question 11

What is the role of the template strand during transcription?

Accepted Answer

It serves as the pattern for RNA synthesis

Question 12

Which of the following best describes a nucleotide excision repair mechanism?

Accepted Answer

Removal of a damaged DNA segment and replacement with new nucleotides

Question 13

If a DNA sequence $$5'	ext{ATG GCT TAA}$$ undergoes a deletion of the first G, what is the new amino acid sequence?

Accepted Answer

A frameshift resulting in a completely different sequence

Question 14

Which process can result in different proteins from the same mRNA?

Accepted Answer

Splicing

Question 15

What is a thymine dimer?

Accepted Answer

A covalent bond between two adjacent thymine bases

Question 16

Which of the following is a consequence of a silent mutation?

Accepted Answer

No change in the amino acid sequence

Question 17

A mutation in the DNA sequence $$5'	ext{GCUACGGAGCUUTAGC}$$ changes the codon $$	ext{GCU} to$$ $$	ext{GCC}. $$What is the effect?

Accepted Answer

No change in the amino acid sequence (silent mutation)

Question 18

Which of the following is NOT a part of a mature mRNA molecule?

Accepted Answer

Introns

Question 19

If a mutation changes the DNA sequence $$5'	ext{ATG GCT TAA} to$$ $$5'	ext{ATG GCT TGA}$$, what is the effect?

Accepted Answer

No effect, both TAA and TGA are stop codons

Question 20

Which of the following best describes the coding strand of DNA?

Accepted Answer

It has the same sequence as the mRNA (except T for U)

Genetic Code, Mutations, and DNA Repair: Study Notes for General Biology

Study Guide - Practice Questions