Question 1

Which of the following is NOT one of the four essential characteristics that a molecule must exhibit to serve as genetic material?

Accepted Answer

It must be able to catalyze protein synthesis.

Question 2

In the Hershey-Chase experiment, which radioisotope was used to label DNA, and what was the main conclusion of the experiment?

Accepted Answer

$$^{32}\mathrm{P}$$; DNA is the genetic material that enters the bacterial cell and directs viral reproduction.

Question 3

Which of the following statements best explains why proteins were initially favored as the genetic material over DNA before 1944?

Accepted Answer

Proteins are more abundant and chemically diverse than DNA.

Question 4

Which experimental result from Griffith’s transformation experiment provided evidence for a 'transforming principle'?

Accepted Answer

Mice injected with a mixture of heat-killed virulent (IIIS) and living avirulent (IIR) bacteria died, and living IIIS bacteria were recovered.

Question 5

Which of the following is an example of direct evidence that DNA is the genetic material in eukaryotes?

Accepted Answer

Production of human insulin by bacteria containing recombinant human DNA.

Question 6

Which enzyme is responsible for synthesizing DNA from an RNA template in retroviruses?

Accepted Answer

Reverse transcriptase

Question 7

Which of the following correctly describes the chemical difference between ribose and deoxyribose?

Accepted Answer

Ribose has a hydroxyl group ($$-OH) at $$the 2' carbon, while deoxyribose has a hydrogen ($$-H) at $$the 2' carbon.

Question 8

Which of the following base pairs is stabilized by three hydrogen bonds in the DNA double helix?

Accepted Answer

Guanine–Cytosine (G–C)

Question 9

Which of the following best describes the directionality of the two strands in the Watson-Crick DNA double helix model?

Accepted Answer

The two strands are antiparallel, one running 5' to 3' and the other 3' to 5'.

Question 10

Which analytical technique separates DNA fragments based on size using a porous matrix?

Accepted Answer

Electrophoresis

Question 11

A DNA sample is heated, causing its absorbance at 260 nm to increase. What is this phenomenon called, and what does it indicate?

Accepted Answer

Hyperchromic shift; it indicates denaturation of the DNA double helix.

Question 12

Which of the following is a unique feature of Z-DNA compared to B-DNA?

Accepted Answer

Z-DNA is a left-handed double helix, while B-DNA is right-handed.

Question 13

Which of the following statements about RNA is FALSE?

Accepted Answer

RNA contains the base thymine instead of uracil.

Question 14

Which class of RNA serves as the template for protein synthesis by carrying genetic information from the gene to the ribosome?

Accepted Answer

Messenger RNA (mRNA)

Question 15

Which bond links nucleotides together in a single strand of DNA?

Accepted Answer

Phosphodiester bond

Question 16

A scientist isolates a nucleic acid from a virus and finds that it contains uracil, ribose, and is single-stranded. Which type of nucleic acid is this most likely to be?

Accepted Answer

RNA

Question 17

Which of the following best describes the role of nucleoside triphosphates (NTPs) in nucleic acid synthesis?

Accepted Answer

They serve as precursor molecules, providing energy for the addition of nucleotides to a growing chain.

Question 18

Which of the following is an example of indirect evidence supporting DNA as the genetic material in eukaryotes?

Accepted Answer

A close correlation between the amount of DNA and the number of chromosome sets in gametes and diploids.

Question 19

Which of the following best explains why UV light at 260 nm is most effective at inducing mutations in DNA?

Accepted Answer

DNA absorbs UV light maximally at 260 nm, which matches the action spectrum for mutagenesis.

DNA Structure and Analysis: Study Notes for Genetics Students

Study Guide - Practice Questions

Study Guide - Flashcards