$$\text{Nucleotide}_1 + \text{Nucleotide}_2 \rightarrow \text{Nucleotide}_1\text{-}$$Nucleotide_2$$ + \text{H}_2\text{O}$$

$$\text{NTP} \rightarrow \text{NMP} + 2\text{P}_i + \text{energy}$$

Question 1

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

Accepted Answer

A fatty acid chain

Question 3

Which nitrogenous base is found only in DNA and not in RNA?

Accepted Answer

Thymine

Question 4

What type of bond forms between the phosphate group on the 5' carbon of one nucleotide and the hydroxyl group on the 3' carbon of another nucleotide?

Accepted Answer

Phosphodiester bond

Question 5

Which equation best represents the condensation reaction that forms a phosphodiester linkage between two nucleotides?

Accepted Answer

$$	ext{Nucleotide}_1 + 	ext{Nucleotide}_2 ightarrow 	ext{Nucleotide}_1	ext{-}$$Nucleotide_2$$ + 	ext{H}_2	ext{O}$$

Question 6

Which of the following statements about DNA structure is correct?

Accepted Answer

DNA strands are antiparallel and twist together to form a double helix.

Question 7

If a DNA molecule contains 30% adenine, what percentage of guanine would you expect to find?

Accepted Answer

20%

Question 8

Which of the following is a major difference between DNA and RNA?

Accepted Answer

DNA contains deoxyribose, while RNA contains ribose.

Question 9

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

Accepted Answer

DNA is held together by phosphodiester linkages, hydrogen bonds, and hydrophobic interactions.

Question 10

Which of the following is true about RNA’s secondary structure?

Accepted Answer

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

Question 11

Which equation best represents the energy change when an activated nucleotide polymerizes?

Accepted Answer

$$	ext{NTP} ightarrow 	ext{NMP} + 2	ext{P}_i + 	ext{energy}$$

Question 12

Which of the following is a function of histone proteins in DNA tertiary structure?

Accepted Answer

Histones help DNA wrap and compact into three-dimensional structures.

Question 13

Which of the following statements about ribozymes is correct?

Accepted Answer

Ribozymes are RNA molecules that catalyze reactions.

Question 14

A scientist discovers a nucleic acid molecule with the following sequence: AUGCUA. Which type of nucleic acid is this most likely to be?

Accepted Answer

RNA, because it contains uracil.

Question 15

Which of the following best describes the process of DNA replication?

Accepted Answer

DNA strands are separated, free nucleotides pair with complementary bases, and phosphodiester linkages form to create new strands.

Question 16

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

Accepted Answer

PCR (polymerase chain reaction) relies on complementary base pairing to amplify DNA.

Question 17

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

Accepted Answer

RNA contains a hydroxyl group on the 2' carbon of ribose, making it more reactive.

Question 18

Which of the following is NOT a function of RNA?

Accepted Answer

Storing genetic information as the primary molecule in all modern cells

Question 19

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

Accepted Answer

RNA secondary structures fold into more complex three-dimensional shapes.

Question 20

Which of the following is a plausible consequence if DNA were not a stable molecule?

Accepted Answer

Organisms would be unable to reliably store and transmit genetic information.

Chapter 4: Nucleic Acids and the RNA World – Study Notes

Study Guide - Practice Questions