Question 1

Which experiment provided the strongest evidence that DNA, and not protein, is the genetic material in cells?

Accepted Answer

Hershey-Chase experiment using bacteriophages

Question 2

What is the significance of Chargaff’s Rule in the structure of DNA?

Accepted Answer

It shows that the number of purines always equals the number of pyrimidines.

Question 3

Which scientist’s X-ray crystallography images were critical in determining the double helix structure of DNA?

Accepted Answer

Rosalind Franklin

Question 4

During DNA replication, why are Okazaki fragments formed?

Accepted Answer

Because DNA polymerase can only add nucleotides to the 3’ end, and the lagging strand is synthesized discontinuously.

Question 5

Which of the following best describes the role of telomeres in eukaryotic chromosomes?

Accepted Answer

They protect chromosome ends from deterioration during replication.

Question 6

A mutation causes a eukaryotic cell to lose the ability to add a 5’ cap to its mRNA. What is the most likely consequence?

Accepted Answer

The mRNA will not be translated efficiently and may be degraded quickly.

Question 7

Which of the following statements about the central dogma of molecular biology is correct?

Accepted Answer

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

Question 8

In eukaryotic cells, which process removes introns from pre-mRNA?

Accepted Answer

Splicing

Question 9

Which of the following best explains why the genetic code is described as ‘redundant’?

Accepted Answer

Some amino acids are coded for by more than one codon.

Question 10

A scientist observes that a eukaryotic gene can produce several different proteins. Which process most likely explains this observation?

Accepted Answer

Alternative splicing

Question 11

Which of the following is true about the origins of replication in prokaryotes and eukaryotes?

Accepted Answer

Eukaryotes have multiple origins, prokaryotes usually have one.

Question 12

Which of the following best describes euchromatin?

Accepted Answer

It is less condensed and transcriptionally active.

Question 13

Which enzyme is responsible for synthesizing the RNA primer during DNA replication?

Accepted Answer

Primase

Question 14

A mutation in the gene encoding histone proteins would most likely affect which process?

Accepted Answer

The packaging of DNA into chromosomes

Question 15

Which of the following is a key difference between transcription in prokaryotes and eukaryotes?

Accepted Answer

Eukaryotes process pre-mRNA by adding a 5’ cap and poly-A tail.

Question 16

Which site on the ribosome does the tRNA carrying the next amino acid enter during translation?

Accepted Answer

A site

Question 17

If a DNA strand has the sequence 5’-ATCGGCTA-3’, what is the complementary sequence?

Accepted Answer

3’-TAGCCGAT-5’

Question 18

Which of the following statements about codons is correct?

Accepted Answer

Codons are universal among almost all organisms.

Question 19

Which process is directly responsible for the synthesis of polypeptide chains?

Accepted Answer

Translation

Question 20

A patient’s cells are found to have abnormally short chromosomes after several rounds of cell division. Which enzyme is most likely defective?

Accepted Answer

Telomerase

Molecular Basis of Inheritance and Gene Expression (Chapters 16-17) – Study Guide

Study Guide - Practice Questions