Question 1

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

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 2

A mutation changes the DNA sequence from 5'-ATG GAA TTT-3' to 5'-ATG GAG TTT-3'. What type of mutation is this, and what is its likely effect on the protein?

Accepted Answer

Silent mutation; no change in the amino acid sequence.

Question 3

Which of the following statements about the genetic code is correct?

Accepted Answer

The genetic code is redundant, with some amino acids specified by more than one codon.

Question 4

During transcription in eukaryotes, which of the following modifications occurs to the pre-mRNA before it leaves the nucleus?

Accepted Answer

Addition of a 5' cap and a poly-A tail, and removal of introns.

Question 5

A tRNA has the anticodon 5'-GAA-3'. Which mRNA codon will it recognize, and which amino acid will it carry if the genetic code table shows GAA codes for Glu?

Accepted Answer

5'-UUC-3'; the tRNA will carry Glu

Question 6

Which of the following is NOT a function of the 5' cap and poly-A tail added to eukaryotic mRNA?

Accepted Answer

Directly code for amino acids in the protein

Question 7

Which enzyme is responsible for catalyzing the attachment of an amino acid to its corresponding tRNA?

Accepted Answer

Aminoacyl-tRNA synthetase

Question 8

In a eukaryotic cell, where does translation occur?

Accepted Answer

On ribosomes in the cytoplasm

Question 9

A mutation causes the insertion of a single nucleotide in the coding region of a gene. What is the most likely consequence?

Accepted Answer

A frameshift mutation

Question 10

Which of the following best explains why a single gene can code for multiple proteins in eukaryotes?

Accepted Answer

Alternative RNA splicing

Question 11

Which of the following is true regarding the flow of genetic information in prokaryotes?

Accepted Answer

Translation can begin before transcription is complete.

Question 12

A scientist introduces a gene from a jellyfish into a pig, and the pig expresses the gene by glowing under UV light. What does this experiment demonstrate?

Accepted Answer

The genetic code is universal among organisms.

Question 13

Which of the following mutations would NOT result in a frameshift?

Accepted Answer

Deletion of three nucleotides in a coding region

Question 14

Which of the following is NOT a component of the transcription initiation complex in eukaryotes?

Accepted Answer

tRNA

Question 15

Which of the following best describes the role of ribozymes in the cell?

Accepted Answer

They are RNA molecules that function as enzymes, such as in RNA splicing.

Question 16

A protein is found to have four distinct polypeptide chains. What is the highest level of structure this protein exhibits?

Accepted Answer

Quaternary structure

Question 17

Which of the following is a direct result of a nonsense mutation?

Accepted Answer

A codon is changed to a stop codon, resulting in a truncated protein.

Question 18

Which of the following best explains why antibiotics can target bacterial ribosomes without harming eukaryotic ribosomes?

Accepted Answer

Bacterial ribosomes are structurally different from eukaryotic ribosomes.

Question 19

Which of the following is NOT a possible final product of gene expression?

Accepted Answer

A carbohydrate

Question 20

Which of the following best describes the function of the signal-recognition particle (SRP) during translation?

Accepted Answer

It escorts the ribosome to the endoplasmic reticulum for protein targeting.

Gene Expression: From Gene to Protein

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