Question 1

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

DNA codes for RNA, which codes for proteins.

Question 2

During transcription, which enzyme is responsible for synthesizing RNA from a DNA template?

Accepted Answer

RNA polymerase

Question 3

A DNA strand has the sequence 3'-TAC GGA TCA-5'. What is the sequence of the mRNA transcript produced from this template?

Accepted Answer

5'-AUG CCU AGU-3'

Question 4

Which of the following statements about RNA processing in eukaryotes is TRUE?

Accepted Answer

Introns are spliced out and exons are joined together.

Question 5

What is the function of the 5' cap and poly-A tail added to eukaryotic mRNA?

Accepted Answer

They facilitate export from the nucleus, protect mRNA from degradation, and help ribosomes attach.

Question 6

A point mutation changes a codon from UAU (tyrosine) to UAA (stop). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 7

If a DNA sequence is mutated by the insertion of one nucleotide, what is the most likely effect on the protein?

Accepted Answer

A frameshift mutation will occur, changing all subsequent amino acids.

Question 8

Which of the following best explains why silent mutations do not affect protein function?

Accepted Answer

The genetic code is redundant, so multiple codons can code for the same amino acid.

Question 9

In the Hershey-Chase experiment, which molecule was shown to carry genetic information into the bacterial cell?

Accepted Answer

DNA

Question 10

A mutation changes the DNA sequence from 3'-TAC CAA GTA GAC TGG GGA CTT CTT-5' to 3'-TAC CAA GTG GAC TGG GGA CTT CTT-5'. The resulting protein is unchanged. What type of mutation is this?

Accepted Answer

Silent mutation

Question 11

Which of the following is NOT a function of ribosomes during translation?

Accepted Answer

Synthesizing RNA from DNA

Question 12

Given the mRNA sequence 5'-AUG GAA UGA-3', what is the resulting amino acid sequence?

Accepted Answer

Met-Glu

Question 13

Which of the following best describes the difference between transcription in prokaryotes and eukaryotes?

Accepted Answer

Transcription and translation occur simultaneously in prokaryotes, but separately in eukaryotes.

Question 14

A mutation changes a codon from GAA (glutamic acid) to GUA (valine). What type of mutation is this?

Accepted Answer

Missense mutation

Question 15

Which of the following is TRUE about alternative splicing?

Accepted Answer

It allows a single gene to code for multiple protein isoforms.

Question 16

What is the correct sequence of events in gene expression?

Accepted Answer

DNA → transcription → RNA → translation → protein

Question 17

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

Accepted Answer

All amino acids after the mutation are changed.

Question 18

Which of the following best describes the role of tRNA during translation?

Accepted Answer

tRNA brings amino acids to the ribosome and matches them to the mRNA codons.

Question 19

If a mutation changes a codon from UGG (tryptophan) to UGA (stop), what is the most likely effect on the protein?

Accepted Answer

The protein will be truncated and likely nonfunctional.

Question 20

Which of the following is TRUE regarding the directionality of transcription?

Accepted Answer

RNA polymerase reads the DNA template strand from 3' to 5' and synthesizes RNA from 5' to 3'.

Gene Expression: Transcription, Translation, and Mutations

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