$$\text{Sugar} + \text{Base} \rightarrow \text{Nucleoside} + H_2O$$

Question 1

Which component of a nucleotide is responsible for the negative charge of DNA molecules?

Accepted Answer

The phosphate group

Question 2

What is the main structural difference between ribose and deoxyribose sugars?

Accepted Answer

Deoxyribose lacks an oxygen atom at the 2' carbon

Question 3

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

Accepted Answer

Uracil

Question 4

In the process of gene expression, what is the correct sequence of events?

Accepted Answer

Replication → Transcription → Translation

Question 5

Which bond connects the 3' carbon of one nucleotide to the 5' carbon of another in a polynucleotide chain?

Accepted Answer

Phosphodiester bond

Question 6

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

Accepted Answer

Adenine

Question 7

What is the directionality of DNA synthesis?

Accepted Answer

5' to 3'

Question 8

A mutation occurs in the DNA sequence. Which process is most likely to be directly affected first?

Accepted Answer

Transcription

Question 9

Which equation best represents the formation of a glycosidic bond between a sugar and a nitrogenous base?

Accepted Answer

$$	ext{Sugar} + 	ext{Base} ightarrow 	ext{Nucleoside} + H_2O$$

Question 10

Which of the following best describes the backbone of a DNA molecule?

Accepted Answer

Alternating sugars and phosphates

Question 11

If a DNA strand has the sequence 5'-ATCG-3', what would be the complementary strand?

Accepted Answer

3'-TAGC-5'

Question 12

Which of the following is NOT a function of nucleic acids?

Accepted Answer

Catalyzing metabolic reactions

Question 13

Which of the following statements about polynucleotides is correct?

Accepted Answer

They are polymers made of nucleotide monomers

Question 14

Which base pairing is correct in DNA?

Accepted Answer

Guanine pairs with Cytosine

Question 15

Which of the following is a pyrimidine found in DNA but not in RNA?

Accepted Answer

Thymine

Question 16

What is the chemical formula for the phosphate group found in nucleotides?

Accepted Answer

$$PO_4$$^{3-}$$

Question 17

Which process involves the movement of mRNA from the nucleus to the cytoplasm?

Accepted Answer

mRNA export

Question 18

Which of the following is true about the sequence of bases in DNA?

Accepted Answer

It is unique for each gene

Question 19

Which bond is formed between the nitrogenous base and the sugar in a nucleotide?

Accepted Answer

Glycosidic bond

Question 20

Which of the following best explains why DNA is synthesized in the 5' to 3' direction?

Accepted Answer

Because nucleotides are added to the 3' hydroxyl group of the growing strand

Nucleic Acids: Structure, Function, and Gene Expression

Study Guide - Practice Questions