Question 1

Which of the following best describes the primary structure of a nucleic acid?

Accepted Answer

The covalent sequence of nucleotides linked by 5'-3' phosphodiester bonds

Question 2

A DNA molecule with a higher GC content will have which of the following properties compared to a DNA molecule with lower GC content?

Accepted Answer

Higher melting temperature ($$T_m)$$

Question 3

Which enzyme is responsible for covalently joining the 3' end of one DNA strand to the 5' end of another during recombinant DNA technology?

Accepted Answer

DNA Ligase

Question 4

During the Sanger method of DNA sequencing, what is the role of dideoxynucleoside triphosphates (ddNTPs)?

Accepted Answer

They terminate DNA strand elongation by lacking a 3'-OH group

Question 5

Which of the following best explains why PCR requires a thermostable DNA polymerase such as Taq polymerase?

Accepted Answer

It survives the high temperatures required for DNA denaturation

Question 6

Which of the following statements about B-form DNA is CORRECT?

Accepted Answer

It has about 10.5 base pairs per turn

Question 7

A researcher wants to separate DNA fragments by size. Which technique should they use?

Accepted Answer

Gel electrophoresis

Question 8

Which of the following is a consequence of base pairing and complementarity in DNA?

Accepted Answer

Genetic information can be copied into RNA or a new DNA strand

Question 9

Which of the following best describes a hairpin structure in nucleic acids?

Accepted Answer

A region where a single strand folds back on itself due to self-complementarity

Question 10

In the context of chromatin structure, what is a nucleosome?

Accepted Answer

A complex of DNA wrapped around a core of eight histone proteins

Question 11

Which of the following is TRUE regarding the A-form of DNA?

Accepted Answer

It is a right-handed helix that forms under dehydrated conditions

Question 12

Which of the following best describes the function of restriction endonucleases in molecular cloning?

Accepted Answer

They cleave DNA at specific palindromic sequences

Question 13

A patient is tested for SARS-CoV-2 using a qRT-PCR assay. Why is reverse transcriptase required in this test?

Accepted Answer

To convert viral RNA into complementary DNA (cDNA) for PCR amplification

Question 14

Which of the following is a property of G-quadruplex (G-tetraplex) DNA structures?

Accepted Answer

They are stabilized by Hoogsteen hydrogen bonds between guanines

Question 15

Which of the following is a direct application of recombinant DNA technology?

Accepted Answer

Insertion of a gene from one organism into another to create a transgenic organism

Question 16

Which of the following statements about RNA structure is CORRECT?

Accepted Answer

RNA can form complex tertiary structures including helices, loops, and bulges

Question 17

A scientist is using PCR to amplify a specific DNA sequence. Which of the following steps is NOT required for PCR?

Accepted Answer

Addition of DNA ligase

Question 18

Which of the following best explains why DNA denaturation (melting) is reversible?

Accepted Answer

Hydrogen bonds between complementary bases can reform upon cooling

Question 19

Which of the following is a key difference between DNA replication and transcription?

Accepted Answer

Replication copies the entire genome, while transcription copies specific genes into RNA

Question 20

Which of the following best describes the role of histones in chromatin structure?

Accepted Answer

They package DNA into nucleosomes, aiding in compaction and regulation

Nucleic Acid Structure and Techniques – Biochemistry Study Notes

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