Question 1

Which experiment provided the first direct evidence that DNA, and not protein, is the genetic material in phages?

Accepted Answer

Hershey and Chase’s radioisotope labeling experiment

Question 2

Which property is NOT required for a molecule to serve as genetic material, according to Francis Crick’s criteria?

Accepted Answer

Ability to catalyze metabolic reactions

Question 3

In the classic Griffith experiment, what was the outcome when mice were injected with a mixture of heat-killed virulent (S) bacteria and live avirulent (R) bacteria?

Accepted Answer

The mice died, and S bacteria were recovered

Question 4

Which of the following best describes the chemical difference between DNA and RNA?

Accepted Answer

DNA contains deoxyribose and thymine; RNA contains ribose and uracil

Question 5

Which of the following statements about Chargaff’s rules is CORRECT?

Accepted Answer

$$A = T$$ and $$G = C in $$DNA from any species

Question 6

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

Accepted Answer

Phosphodiester bonds

Question 7

A DNA molecule is found to have 30% adenine. According to Chargaff’s rules, what percentage of guanine would you expect?

Accepted Answer

20%

Question 8

Which of the following is a purine base found in nucleic acids?

Accepted Answer

Adenine

Question 9

What is the significance of Rosalind Franklin’s X-ray diffraction studies for the discovery of DNA structure?

Accepted Answer

They revealed the helical structure and periodicity of DNA

Question 10

Which of the following best describes the directionality of DNA strands in the double helix?

Accepted Answer

The two strands are antiparallel: one runs 5’ to 3’, the other 3’ to 5’

Question 11

Which of the following is NOT a function of nucleoside triphosphates (NTPs) in cells?

Accepted Answer

Forming peptide bonds during translation

Question 12

Which analytical technique is used to separate DNA fragments by size?

Accepted Answer

Agarose gel electrophoresis

Question 13

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

Accepted Answer

DNA is transcribed into RNA, which is translated into protein

Question 14

Which of the following is a unique RNA found in eukaryotes that is involved in processing mRNAs?

Accepted Answer

snRNA

Question 15

Which alternative DNA conformation is left-handed and has been implicated in gene regulation?

Accepted Answer

Z-DNA

Question 16

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

Accepted Answer

Proteins are composed of 20 different amino acids, providing greater chemical diversity

Question 17

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

Accepted Answer

A nitrogenous base, a pentose sugar, and a phosphate group

Question 18

Which experiment used enzymes to selectively destroy DNA, RNA, or protein to identify the transforming principle?

Accepted Answer

Avery, MacLeod, and McCarty’s experiment

Question 19

Which of the following is a real-world application of fluorescence in situ hybridization (FISH)?

Accepted Answer

Visualizing specific chromosomal regions using fluorescent probes

Question 20

Which of the following best describes the relationship between DNA structure and its function as genetic material?

Accepted Answer

The double helix allows for complementary base pairing, enabling accurate replication and information storage

DNA Structure and Analysis: Key Concepts and Experiments in Genetics

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