Question 1

Which of the following statements best describes the central dogma of molecular genetics?

Accepted Answer

Genetic information flows from DNA to RNA to protein.

Question 2

Which feature distinguishes RNA from DNA at the molecular level?

Accepted Answer

RNA is typically single-stranded and contains uracil instead of thymine.

Question 3

What is the role of mRNA in the process of gene expression?

Accepted Answer

It carries genetic information from DNA and serves as a template for protein synthesis.

Question 4

Which statement about the genetic code is correct?

Accepted Answer

The genetic code is unambiguous; each codon specifies only one amino acid.

Question 5

Why is the genetic code described as 'degenerate'?

Accepted Answer

Because multiple codons can specify the same amino acid.

Question 6

Which amino acids are encoded by only a single codon in the genetic code?

Accepted Answer

Methionine and tryptophan

Question 7

A mutation changes the third base of a codon from C to U, but the amino acid specified does not change. Which concept explains this phenomenon?

Accepted Answer

The wobble hypothesis

Question 8

Which of the following is NOT a function of tRNA?

Accepted Answer

Serving as a template for protein synthesis

Question 9

During transcription in eukaryotes, which enzyme synthesizes RNA using a DNA template?

Accepted Answer

RNA polymerase

Question 10

Which of the following statements about transcription initiation is TRUE?

Accepted Answer

Transcription factors bind to cis-acting DNA elements to recruit RNA polymerase.

Question 11

What is the significance of the Shine-Dalgarno sequence in bacteria?

Accepted Answer

It is the site where ribosomes bind to initiate translation.

Question 12

Which process increases the efficiency of translation by allowing multiple ribosomes to translate a single mRNA simultaneously?

Accepted Answer

Polyribosome formation

Question 13

A single mRNA molecule in a virus encodes overlapping genes with multiple initiation points. What is the result of this arrangement?

Accepted Answer

It creates different reading frames and specifies more than one polypeptide.

Question 14

Which of the following is a correct description of a codon?

Accepted Answer

A sequence of three ribonucleotide bases in mRNA that specifies an amino acid.

Question 15

Which of the following equations correctly represents the number of possible codons given four different RNA bases and codons of length three?

Accepted Answer

$$4^3$$

Question 16

If a mutation causes a shift in the reading frame of an mRNA, what is the likely consequence?

Accepted Answer

All codons downstream of the mutation will be read incorrectly, potentially altering the entire protein sequence.

Question 17

Which of the following is TRUE regarding the process of translation in eukaryotes?

Accepted Answer

It requires a 5' capped mRNA and initiation factors.

Question 18

What is the function of the anticodon region of tRNA?

Accepted Answer

It base-pairs with the complementary codon in mRNA.

Question 19

Which of the following statements about mRNA processing in eukaryotes is correct?

Accepted Answer

Introns are removed and exons are joined together during splicing.

Question 20

A patient has a mutation in a gene that affects the efficiency of RNA polymerase binding. Which region of the gene is most likely mutated?

Accepted Answer

The promoter (a cis-acting DNA element)

RNA, Transcription, and Translation: The Central Dogma and the Genetic Code

Study Guide - Practice Questions