Question 1

Which of the following statements correctly distinguishes DNA from RNA based on their chemical structure?

Accepted Answer

DNA has a deoxyribose sugar, while RNA has a ribose sugar.

Question 2

Which of the following bases is a purine found in both DNA and RNA?

Accepted Answer

Adenine

Question 3

What is the main difference between a nucleoside and a nucleotide?

Accepted Answer

A nucleotide contains a phosphate group, while a nucleoside does not.

Question 4

Which property of nucleotides allows for their detection and quantification in laboratory settings?

Accepted Answer

Their absorption of UV light at around 260 nm

Question 5

Which tautomeric form of guanine is most prevalent under physiological conditions?

Accepted Answer

Keto

Question 6

What type of bond links nucleotides together in a nucleic acid strand?

Accepted Answer

Phosphodiester bond

Question 7

Given the DNA sequence 5'-ACGT-3', what is the complementary sequence?

Accepted Answer

3'-TGCA-5'

Question 8

According to Chargaff's rules, which equation correctly represents the base composition of double-stranded DNA?

Accepted Answer

$$A = T$$ and $$G = C$$

Question 9

How many base pairs are there per turn in the B-form DNA double helix?

Accepted Answer

10 bp/turn

Question 10

What is the distance between successive base pairs in the DNA double helix?

Accepted Answer

$$0.34 \AA$$

Question 11

Which structural feature of DNA is responsible for the formation of major and minor grooves?

Accepted Answer

The space-filling arrangement of atoms in the double helix

Question 12

Which model of DNA replication is supported by experimental evidence?

Accepted Answer

Semiconservative replication

Question 13

Which form of DNA is most commonly found in cells?

Accepted Answer

B-form

Question 14

What is the role of topoisomerases in DNA structure?

Accepted Answer

They modify the state of DNA supercoiling.

Question 15

Which statement best describes the structure of transfer RNA (tRNA)?

Accepted Answer

tRNA is a single-stranded molecule with extensive regions of intramolecular complementarity.

Question 16

Which of the following DNA sequences is palindromic?

Accepted Answer

5'-GAATTC-3'

Question 17

Where are G-quadruplex structures most commonly found in eukaryotic chromosomes?

Accepted Answer

In telomeres

Question 18

What happens to DNA when it is heated above its melting temperature?

Accepted Answer

It denatures into two single strands.

Question 19

Which process converts DNA-based information into messenger RNA (mRNA)?

Accepted Answer

Transcription

Question 20

During translation, what cellular structure is responsible for synthesizing proteins based on mRNA information?

Accepted Answer

Ribosome

Nucleic Acids: Structure, Properties, and Biological Functions

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