$\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}$

Question 1

Which scientist's work was critical in revealing the double helix structure of DNA through X-ray diffraction, but was not awarded the Nobel Prize?

Accepted Answer

Rosalind Franklin

Question 2

Which of the following best describes the antiparallel nature of DNA strands?

Accepted Answer

One strand runs 5' to 3', and the other runs 3' to 5'.

Question 3

During DNA replication, which enzyme is responsible for unwinding the DNA double helix?

Accepted Answer

Helicase

Question 4

If a DNA template strand has the sequence 5'-ATGCGT-3', what is the sequence of the complementary RNA produced during transcription?

Accepted Answer

3'-UACGCA-5'

Question 5

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

Accepted Answer

The genetic code is universal and redundant.

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 modifications occurs to eukaryotic pre-mRNA before it leaves the nucleus?

Accepted Answer

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

Question 8

A mutation changes a codon from UAU to UAA. What is the consequence of this mutation?

Accepted Answer

A nonsense mutation introducing a premature stop codon

Question 9

Which process describes the synthesis of a polypeptide using the information in an mRNA molecule?

Accepted Answer

Translation

Question 10

If a DNA molecule contains 30% adenine, what percentage of guanine would you expect to find?

Accepted Answer

$20\%$

Question 11

Which of the following best explains why the genetic code is described as 'degenerate'?

Accepted Answer

Some amino acids are coded by more than one codon.

Question 12

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

Accepted Answer

Translation of the mRNA

Question 13

Which enzyme catalyzes the formation of phosphodiester bonds between Okazaki fragments during DNA replication?

Accepted Answer

DNA ligase

Question 14

A patient has a mutation that prevents the addition of a 5' cap to mRNA. What is the most likely consequence?

Accepted Answer

The mRNA will be rapidly degraded in the cytoplasm.

Question 15

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

Accepted Answer

$	ext{DNA} ightarrow 	ext{RNA} ightarrow 	ext{Protein}$

Question 16

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

Accepted Answer

It protects mRNA from degradation.

Question 17

Which of the following statements about Okazaki fragments is correct?

Accepted Answer

They are short DNA fragments synthesized on the lagging strand.

Question 18

A mutation in the gene encoding for a tRNA anticodon changes its sequence. What is the most likely effect on translation?

Accepted Answer

The wrong amino acid may be incorporated into the protein.

Question 19

Which of the following best explains why introns are removed from pre-mRNA?

Accepted Answer

They are non-coding sequences that interrupt the coding region.

Question 20

Which of the following is true regarding the direction of synthesis for both DNA and RNA polymerases?

Accepted Answer

Both synthesize nucleic acids in the 5' to 3' direction.

DNA Structure, Replication, Transcription, and Translation: Study Notes for General Biology

Study Guide - Practice Questions