Question 1

Which of the following correctly describes the structural difference between DNA and RNA nucleotides?

Accepted Answer

DNA nucleotides contain deoxyribose sugar, while RNA nucleotides contain ribose sugar.

Question 2

What type of bond connects the phosphate group of one nucleotide to the sugar of the next nucleotide in a nucleic acid strand?

Accepted Answer

Phosphodiester bond

Question 3

If a segment of DNA has the sequence 5'-ATCGGTA-3', what is the complementary sequence on the opposite strand?

Accepted Answer

3'-TAGCCAT-5'

Question 4

Which nitrogenous base is found in RNA but not in DNA?

Accepted Answer

Uracil

Question 5

During DNA replication, what is the role of the leading strand?

Accepted Answer

It is synthesized continuously in the direction of the replication fork.

Question 6

Which of the following best explains why DNA strands are described as 'antiparallel'?

Accepted Answer

One strand runs 5' to 3', while the other runs 3' to 5'.

Question 7

Which equation represents the formation of a phosphodiester bond between two nucleotides?

Accepted Answer

$$\mathrm{Nucleotide}_1 + \mathrm{Nucleotide}_2 \rightarrow \mathrm{Nucleotide}_1{-}P{-}O{-}$$Nucleotide_2$$ + H_2O$$

Question 8

Which statement about complementary base pairing in DNA is correct?

Accepted Answer

Cytosine pairs with guanine via three hydrogen bonds.

Question 9

A mutation changes a cytosine (C) in DNA to a thymine (T). What is the most direct effect on base pairing?

Accepted Answer

The mutated base will now pair with adenine (A) via two hydrogen bonds.

Question 10

Which type of RNA is responsible for bringing amino acids to the ribosome during translation?

Accepted Answer

tRNA (transfer RNA)

Question 11

Which of the following best describes the flow of genetic information in a eukaryotic cell?

Accepted Answer

DNA $$\rightarrow$$ RNA $$\rightarrow$$ Protein

Question 12

Which of the following is NOT a function of DNA?

Accepted Answer

Catalyzing biochemical reactions

Question 13

A scientist isolates a nucleic acid molecule that contains the bases adenine, uracil, cytosine, and guanine. What type of molecule is this?

Accepted Answer

RNA

Question 14

Which of the following statements about the sugar-phosphate backbone of nucleic acids is correct?

Accepted Answer

It provides structural stability to the nucleic acid strand.

Question 15

During transcription, which enzyme synthesizes the mRNA strand complementary to the DNA template?

Accepted Answer

RNA polymerase

Question 16

Which of the following best explains the importance of the sequence of nucleotide bases in DNA?

Accepted Answer

It determines the order of amino acids in proteins.

Question 17

Which type of RNA forms the core structure of the ribosome and catalyzes peptide bond formation?

Accepted Answer

rRNA

Question 18

A DNA molecule is found to have 20% adenine. According to Chargaff's rules, what percentage of guanine would you expect?

Accepted Answer

30%

Question 19

Which process involves the conversion of genetic information from DNA into a polypeptide chain?

Accepted Answer

Translation

Question 20

Which of the following is a real-world consequence of a mutation in DNA?

Accepted Answer

It can lead to changes in protein structure and function, potentially causing genetic diseases.

12-Nucleic Acids: DNA and RNA – Structure, Function, and Roles in Cell Biology

Study Guide - Practice Questions