Question 1

Which of the following statements best describes the RNA world hypothesis?

Accepted Answer

RNA was the first molecule to store genetic information and catalyze its own replication.

Question 2

Which of the following is NOT a component of a nucleotide?

Accepted Answer

A fatty acid tail

Question 3

What is the main structural difference between ribonucleotides and deoxyribonucleotides?

Accepted Answer

Ribonucleotides have an $$-OH$$ group at the 2' carbon, while deoxyribonucleotides have an $$-H at $$the 2' carbon.

Question 4

Which of the following correctly pairs a purine with a pyrimidine found in DNA?

Accepted Answer

Adenine (purine) pairs with Thymine (pyrimidine)

Question 5

During nucleic acid polymerization, what type of bond forms between nucleotides?

Accepted Answer

Phosphodiester bond

Question 6

Which directionality is correct for the sugar-phosphate backbone of nucleic acids?

Accepted Answer

5' to 3'

Question 7

What is the role of nucleoside triphosphates in nucleic acid polymerization?

Accepted Answer

They provide the energy required for polymerization by releasing two phosphate groups.

Question 8

Which experimental evidence was crucial in determining the double helical structure of DNA?

Accepted Answer

X-ray crystallography

Question 9

Why are DNA strands described as antiparallel?

Accepted Answer

One strand runs 5' to 3' and the other runs 3' to 5'.

Question 10

Which of the following best explains why DNA is a stable molecule suitable for information storage?

Accepted Answer

It is stabilized by phosphodiester linkages, hydrogen bonds, and hydrophobic interactions.

Question 11

Which of the following is a unique property of RNA compared to DNA?

Accepted Answer

RNA can act as a catalyst (ribozyme).

Question 12

What is the main function of mRNA in cells?

Accepted Answer

It transmits genetic information from DNA to protein synthesis machinery.

Question 13

Which of the following best describes the secondary structure of RNA?

Accepted Answer

It forms hairpin structures due to complementary base pairing within the same strand.

Question 14

A scientist isolates a nucleic acid with the following characteristics: contains uracil, is single-stranded, and has a ribose sugar. What is the identity of this molecule?

Accepted Answer

RNA

Question 15

Which of the following processes is driven by the hydrolysis of nucleoside triphosphates?

Accepted Answer

Polymerization of nucleic acids

Question 16

Which of the following is a correct statement about DNA replication?

Accepted Answer

Each original strand serves as a template for the synthesis of a new complementary strand.

Question 17

Which of the following best explains why RNA is less stable than DNA?

Accepted Answer

The 2'-OH group on ribose makes RNA more reactive.

Question 18

Which of the following is a real-world application of the complementary base pairing property of DNA?

Accepted Answer

DNA fingerprinting in forensic science

Question 19

A mutation changes a cytosine (C) to a thymine (T) in a DNA strand. Which of the following base pairing changes would you expect in the complementary strand after replication?

Accepted Answer

The complementary base will change from guanine (G) to adenine (A).

Question 20

Which of the following best describes the tertiary structure of DNA in eukaryotic cells?

Accepted Answer

DNA wraps around histone proteins to form compact structures.

Nucleic Acids and the RNA World: Structure and Function of DNA and RNA

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