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

During DNA replication, new nucleotides are added to which part of the growing DNA strand?

Accepted Answer

3' OH of sugar

Question 3

If the DNA template strand has the sequence 3'-TACGGT-5', what is the corresponding mRNA sequence produced during transcription?

Accepted Answer

5'-AUGCCA-3'

Question 4

Which of the following statements about the directionality of nucleic acids is correct?

Accepted Answer

DNA and RNA are synthesized in the 5' to 3' direction.

Question 5

Which enzyme is responsible for catalyzing the synthesis of RNA from a DNA template during transcription?

Accepted Answer

RNA polymerase

Question 6

A mutation changes a codon from 5'-GAG-3' to 5'-GTG-3' in the coding strand of DNA. What is the effect on the protein sequence?

Accepted Answer

The amino acid at this position changes from glutamic acid to valine.

Question 7

Which of the following codons is the start codon for translation in eukaryotes?

Accepted Answer

5'-AUG-3'

Question 8

During translation, the ribosome reads the mRNA in which direction?

Accepted Answer

5' to 3'

Question 9

A tRNA has the anticodon 3'-UAC-5'. Which mRNA codon will it recognize, and which amino acid will it carry?

Accepted Answer

5'-AUG-3'; Methionine

Question 10

Which of the following best explains why the leading and lagging strands are synthesized differently during DNA replication?

Accepted Answer

DNA polymerase can only add nucleotides to the 3' OH, so one strand is synthesized continuously and the other discontinuously.

Question 11

If the mRNA sequence is 5'-GUC-3', which amino acid will be incorporated into the growing polypeptide chain?

Accepted Answer

Valine

Question 12

Which of the following mutations is most likely to result in a truncated (shortened) protein?

Accepted Answer

A nonsense mutation

Question 13

Which of the following statements about peptide bond formation during translation is correct?

Accepted Answer

Peptide bonds are formed between the carboxyl group of one amino acid and the amino group of the next.

Question 14

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

Accepted Answer

The rate of transcription initiation

Question 15

Which of the following is true regarding the coding (sense) strand of DNA?

Accepted Answer

It has the same sequence as the mRNA except T replaces U.

Question 16

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

Accepted Answer

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

Question 17

If a DNA sequence is 5'-ATG GAA TGA-3' (coding strand), what is the corresponding mRNA and amino acid sequence?

Accepted Answer

mRNA: 5'-AUG GAA UGA-3'; Amino acids: Met-Glu-Stop

Question 18

Which of the following is a possible consequence of a single nucleotide deletion in the coding region of a gene?

Accepted Answer

A frameshift mutation, altering all downstream amino acids.

Question 19

Which of the following best explains why multiple ribosomes can translate a single mRNA molecule simultaneously?

Accepted Answer

Ribosomes can attach to the mRNA at different points and move along it independently.

DNA Replication, Transcription, and Translation: The Central Dogma

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