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

Ability to form a triple helix under physiological conditions

Question 2

In the classic Avery, MacLeod, and McCarty experiment, which treatment prevented transformation of avirulent bacteria, demonstrating the identity of the 'transforming principle'?

Accepted Answer

Treatment with DNase

Question 3

Which experimental result from the Hershey–Chase experiment provided direct evidence that DNA, not protein, is the genetic material in bacteriophages?

Accepted Answer

Radioactive phosphorus was found inside the bacterial cells

Question 4

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

Accepted Answer

DNA contains deoxyribose, which has a hydrogen at the 2' carbon

Question 5

A DNA molecule is subjected to increasing temperature, and its absorbance at 260 nm is measured. What is the term for the sharp increase in absorbance as the DNA denatures?

Accepted Answer

Hyperchromic shift

Question 6

Which of the following base composition statements is consistent with Chargaff’s rules for double-stranded DNA?

Accepted Answer

$$[A] = [T]$$ and $$[G] = [C]$$

Question 7

Which analytical technique is most appropriate for separating DNA fragments by size?

Accepted Answer

Electrophoresis

Question 8

A retrovirus such as HIV uses which enzyme to synthesize DNA from its RNA genome?

Accepted Answer

Reverse transcriptase

Question 9

Which of the following statements about the Watson–Crick model of DNA is FALSE?

Accepted Answer

Base pairs are held together by covalent bonds

Question 10

Which form of DNA is most prevalent under physiological (aqueous, low-salt) conditions in cells?

Accepted Answer

B-DNA

Question 11

Which of the following is a direct piece of evidence supporting DNA as the genetic material in eukaryotes?

Accepted Answer

Recombinant DNA technology can produce human proteins in bacteria

Question 12

Which of the following best explains why UV light at 260 nm is mutagenic to cells?

Accepted Answer

DNA and RNA absorb maximally at 260 nm

Question 13

Which of the following is a pyrimidine base found in DNA?

Accepted Answer

Thymine

Question 14

What is the main function of tRNA during translation?

Accepted Answer

Carries amino acids to the ribosome

Question 15

Which of the following bonds links nucleotides together in a single strand of DNA?

Accepted Answer

Phosphodiester bonds

Question 16

A DNA sample has a melting temperature ($$T_m) of 83$$°C, while another has a $$T_m of 77$$°C. What can you infer about their base composition?

Accepted Answer

The sample with $$T_m = 83°C$$ has a higher G-C content

Question 17

Which of the following is TRUE regarding the directionality of nucleic acid synthesis?

Accepted Answer

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

Question 18

Which of the following best describes the process of molecular hybridization?

Accepted Answer

The denaturation and renaturation of nucleic acids from different sources

Question 19

Which of the following is a unique RNA involved in the processing of mRNAs in eukaryotic cells?

Accepted Answer

snRNA

Question 20

Which of the following statements about Z-DNA is correct?

Accepted Answer

It is a left-handed double helix with a zig-zag backbone

DNA Structure and Analysis: Foundations of Genetic Material

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