Question 1

Which of the following best describes the main conclusion of Beadle and Tatum’s experiment with Neurospora crassa?

Accepted Answer

Each gene directly produces a single enzyme, supporting the one gene-one enzyme hypothesis.

Question 2

During eukaryotic transcription, which of the following is NOT a function of the promoter region?

Accepted Answer

It codes for the amino acid sequence of the protein.

Question 3

Which of the following modifications occurs to eukaryotic pre-mRNA before it becomes mature mRNA?

Accepted Answer

Addition of a 5' cap and a poly-A tail

Question 4

A mutation changes the codon UAU (tyrosine) to UAA. What is the most likely effect on the resulting protein?

Accepted Answer

The protein will be prematurely terminated due to a stop codon.

Question 5

Which of the following best describes the process of translation?

Accepted Answer

Synthesis of proteins from an mRNA template

Question 6

What is the role of tRNA during translation?

Accepted Answer

It brings amino acids to the ribosome and matches them to the mRNA codon.

Question 7

Which of the following sequences represents the correct flow of genetic information according to the central dogma of molecular biology?

Accepted Answer

$$DNA \rightarrow RNA \rightarrow Protein$$

Question 8

A eukaryotic gene contains both exons and introns. What happens to these regions during mRNA processing?

Accepted Answer

Introns are removed and exons are spliced together.

Question 9

Which of the following best explains why a single base insertion in a coding region often has a more severe effect than a single base substitution?

Accepted Answer

Insertions cause a frameshift, altering all downstream amino acids.

Question 10

Which of the following events occurs during the elongation phase of translation?

Accepted Answer

Amino acids are added one by one to the growing polypeptide chain.

Question 11

Which of the following is a possible consequence of a nonsense mutation?

Accepted Answer

A stop codon is introduced, leading to a truncated protein.

Question 12

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

Accepted Answer

The genetic code is universal and redundant.

Question 13

Which of the following best describes the function of the 5' cap added to eukaryotic mRNA?

Accepted Answer

It protects mRNA from degradation and assists in ribosome binding.

Question 14

A mutation in the promoter region of a gene would most likely affect which of the following?

Accepted Answer

The rate of transcription initiation

Question 15

Which of the following is true regarding alternative splicing in eukaryotes?

Accepted Answer

It allows a single gene to code for multiple proteins.

Question 16

Which of the following best describes the role of RNA polymerase during transcription?

Accepted Answer

It synthesizes RNA from a DNA template.

Question 17

A patient has a genetic disorder caused by a single nucleotide substitution that changes a codon from GAG to GTG in the beta-globin gene. What is the most likely result?

Accepted Answer

A missense mutation resulting in sickle cell hemoglobin

Question 18

Which of the following is NOT a step in the processing of eukaryotic pre-mRNA?

Accepted Answer

Replication of the mRNA

Question 19

Which of the following best explains why not all mutations in DNA result in a change in the protein sequence?

Accepted Answer

Some mutations are silent due to the redundancy of the genetic code.

Question 20

Which of the following is a function of the poly-A tail added to eukaryotic mRNA?

Accepted Answer

It protects mRNA from degradation and aids in export from the nucleus.

Chapter 14: Gene Expression – From Gene to Protein (Study Guide)

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