Nucleic Acids: Structure, Properties, and Reactions - Interactive Learning Quizzes

Question 1

Identify the key structural differences between DNA and RNA:

Accepted Answer

DNA has a double helix structure, while RNA has a single helix structure.

Accepted Answer

DNA contains deoxyribose sugar, while RNA contains ribose sugar.

Accepted Answer

DNA has thymine, while RNA has uracil.

Answer

DNA is found in the nucleus, while RNA is found in the cytoplasm.

Question 2

How can mutations in DNA potentially affect an organism?

Accepted Answer

Alter gene function, changing protein structure and function

Answer

Always result in harmful changes

Answer

Only affect DNA structure, not gene function

Answer

Exclusively occur in non-coding regions, having no impact

Question 3

Which protein is responsible for catalyzing and extending new DNA strands during replication?

Accepted Answer

DNA polymerase

Answer

Helicase

Answer

Primase

Answer

Topoisomerase

Question 4

Which of the following is NOT a nitrogenous base found in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Guanine

Answer

Cytosine

Question 5

The process by which DNA makes a copy of itself is called:

Accepted Answer

Replication

Answer

Transcription

Answer

Translation

Answer

Mutation

Question 6

Which of the following enzymes is responsible for unwinding DNA during replication?

Accepted Answer

Helicase

Answer

DNA polymerase

Answer

Primase

Answer

Ligase

Question 7

What type of chemical bond is formed between complementary nitrogenous base pairs?

Accepted Answer

Hydrogen bond

Answer

Covalent bond

Answer

Ionic bond

Answer

Base pair

Question 8

What is the primary function of ribosomes in protein synthesis?

Accepted Answer

To assemble amino acids into proteins

Answer

To synthesize mRNA

Answer

To regulate gene expression

Answer

To transport RNA molecules

Question 9

Which technique is commonly used to separate DNA fragments based on their size?

Accepted Answer

Gel electrophoresis

Answer

Polymerase Chain Reaction (PCR)

Answer

DNA sequencing

Answer

Chromatography

Question 10

What is the significance of the central dogma of molecular biology?

Accepted Answer

It describes the flow of genetic information from DNA to RNA to protein.

Answer

It explains how mutations can occur in DNA and RNA.

Answer

It predicts the structure of proteins based on their amino acid sequence.

Answer

It identifies the role of ribosomes in protein synthesis.

Question 11

Which factor primarily influences the stability of a double-stranded DNA molecule?

Accepted Answer

Number of hydrogen bonds between nitrogenous bases

Answer

Length of the DNA molecule

Answer

Presence of modified bases in the DNA sequence

Answer

Presence of supercoiling in the DNA molecule

Question 12

What is the process by which RNA is synthesized using DNA as a template?

Accepted Answer

Transcription

Answer

Replication

Answer

Translation

Answer

Mutation

Question 13

Which of the following enzymes is responsible for unwinding the DNA double helix during replication?

Accepted Answer

Helicase

Answer

Polymerase

Answer

Ligase

Answer

Topoisomerase

Question 14

What type of bond links adjacent nucleotides in a nucleic acid chain?

Accepted Answer

Phosphodiester bond

Answer

Glycosidic bond

Answer

Hydrogen bond

Answer

Ionic bond

Question 15

What is the name of the double-stranded structure formed by the hybridization of complementary DNA or RNA strands?

Accepted Answer

Double helix

Answer

Hybridization probe

Answer

Gel electrophoresis

Answer

PCR product

Question 16

What is the term for the sequence of nitrogenous bases in a DNA molecule?

Accepted Answer

Sequence

Answer

Genome

Answer

Gene

Answer

Codon

Question 17

Which type of nucleic acid is responsible for carrying genetic information and is composed of deoxyribonucleotides?

Accepted Answer

DNA

Answer

RNA

Answer

Protein

Answer

Lipid

Question 18

The complementary base pairing between adenine and thymine (or uracil in RNA) allows for:

Accepted Answer

Accurate DNA replication

Answer

Efficient protein synthesis

Answer

Genetic variation

Answer

Regulation of gene expression

Question 19

Which of the following enzymes is responsible for catalyzing the addition of RNA nucleotides during transcription?

Accepted Answer

RNA polymerase

Answer

DNA polymerase

Answer

Helicase

Answer

Topoisomerase

Question 20

The process of unwinding and separating the DNA double helix is facilitated by:

Accepted Answer

Helicase

Answer

Gyrase

Answer

Primase

Answer

Polymerase

Question 21

Which of the following is NOT a structural difference between DNA and RNA?

Accepted Answer

Double-stranded structure

Answer

Sugar molecule

Answer

Nitrogenous base composition

Answer

Presence of introns

Question 22

The phenomenon of genetic code redundancy refers to the fact that:

Accepted Answer

Multiple codons can code for the same amino acid

Answer

All amino acids are coded by a single codon

Answer

The genetic code is universal across all living organisms

Answer

Protein synthesis is always error-free

Question 23

Which of the following techniques is commonly used for DNA sequencing and involves the use of chain-terminating dideoxynucleotides?

Accepted Answer

Sanger sequencing

Answer

Polymerase chain reaction

Answer

Gel electrophoresis

Answer

X-ray crystallography

Question 24

The structure of DNA, as proposed by Watson and Crick in 1953, was primarily determined using:

Accepted Answer

X-ray crystallography

Answer

Microscopy

Answer

Chromatography

Answer

Mass spectrometry

Question 25

How do introns and exons contribute to gene expression regulation in eukaryotes?

Accepted Answer

Introns are removed, and exons are spliced to produce different mRNA molecules that code for different proteins.

Answer

Exons are spliced during translation to form a continuous sequence of codons.

Answer

Introns contain regulatory sequences that control transcription and translation.

Answer

Exons provide structural support to mRNA molecules.

Question 26

Explain RNA interference (RNAi), highlighting its mechanism and potential applications in biomedical research and therapeutics.

Accepted Answer

RNAi uses small RNA molecules to selectively target and silence specific genes.

Answer

RNAi is solely used for gene silencing, with no therapeutic applications.

Answer

RNAi is exclusively employed in research settings, with no clinical relevance.

Answer

RNAi exclusively targets DNA, leaving RNA transcription unaffected.

Question 27

The fundamental building block of a nucleic acid is known as a:

Accepted Answer

Nucleotide

Answer

Amino acid

Answer

Monosaccharide

Answer

Polypeptide

Question 28

The distinctive double-helix structure of DNA is primarily stabilized by:

Accepted Answer

Hydrogen bonds

Answer

Covalent bonds

Answer

Van der Waals forces

Answer

Ionic bonds

Question 29

Which of the following is a primary function of DNA in cells?

Accepted Answer

Store genetic information

Answer

Provide energy for cell processes

Answer

Catalyze biochemical reactions

Answer

Transport molecules across the cell membrane

Question 30

The process of synthesizing a DNA strand complementary to an RNA template is known as:

Accepted Answer

Reverse transcription

Answer

Translation

Answer

Replication

Answer

Transcription

Question 31

Gel electrophoresis is a technique commonly used to:

Accepted Answer

Separate DNA fragments based on size

Answer

Determine the sequence of DNA

Answer

Quantify the concentration of DNA

Answer

Amplify DNA fragments

Question 32

The genetic code consists of groups of how many nucleotides?

Accepted Answer

Triplet

Answer

Quadruplet

Answer

Random

Answer

Doublet

Question 33

Which of the following factors significantly influences the stability of a DNA molecule?

Accepted Answer

pH and temperature

Answer

Light intensity

Answer

Magnetic fields

Answer

Sound waves

Question 34

Which of the following statements about nucleic acids is incorrect?

Accepted Answer

Nucleic acids always have a double-stranded structure.

Answer

Nucleic acids are made up of nucleotide subunits.

Answer

Nucleic acids carry genetic information.

Question 35

Which of the following is NOT a type of nucleic acid?

Accepted Answer

Protein

Answer

DNA

Answer

RNA

Question 36

Which of the following is the function of RNA polymerase?

Accepted Answer

To synthesize RNA from a DNA template

Answer

To unwind the DNA double helix

Answer

To stabilize the DNA-RNA hybrid

Answer

To remove introns from the RNA transcript

Question 37

Which of the following is a type of covalent bond that forms between adjacent nucleotides in a nucleic acid molecule?

Accepted Answer

Phosphodiester bond

Answer

Hydrogen bond

Answer

Peptide bond

Answer

Glycosidic bond

Question 38

Which of the following is a function of tRNA?

Accepted Answer

To carry amino acids to the ribosome during protein synthesis

Answer

To catalyze biochemical reactions

Answer

To store genetic information

Question 39

Which of the following is a characteristic of RNA that distinguishes it from DNA?

Accepted Answer

Contains uracil instead of thymine

Answer

Is a double-stranded molecule

Answer

Has a higher molecular weight

Answer

Is always found in the nucleus

Question 40

Which of the following is a technique used to separate fragments of DNA based on size?

Accepted Answer

Gel electrophoresis

Answer

Southern blotting

Answer

DNA sequencing

Answer

Polymerase chain reaction

Question 41

Which of the following is the central dogma of molecular biology?

Accepted Answer

DNA → RNA → Protein

Answer

DNA → Protein → RNA

Answer

RNA → DNA → Protein

Answer

Protein → RNA → DNA

Question 42

Which of the following is NOT a nitrogenous base found in nucleic acids?

Accepted Answer

Uracil

Answer

Adenine

Answer

Guanine

Question 43

The sugar-phosphate backbone of a polynucleotide chain runs in an:

Accepted Answer

Antiparallel direction

Answer

Parallel direction

Answer

Circular direction

Question 44

Which type of bond links adjacent nucleotides in a polynucleotide chain?

Accepted Answer

Phosphodiester bond

Answer

Hydrogen bond

Answer

Covalent bond

Answer

Glycosidic bond

Question 45

The double-helical structure of DNA is maintained by:

Accepted Answer

Hydrogen bonding between complementary nitrogenous bases

Answer

Covalent bonding between the sugar-phosphate backbones

Answer

Ionic bonding between the negatively charged phosphate groups

Question 46

Which enzyme is responsible for unwinding the DNA double helix prior to replication?

Accepted Answer

Helicase

Answer

Polymerase

Answer

Topoisomerase

Answer

Primase

Question 47

What is the difference between DNA and RNA?

Accepted Answer

RNA contains uracil instead of thymine and has a single-stranded structure

Answer

RNA contains ribose instead of deoxyribose and has a double-stranded structure

Answer

DNA contains adenine instead of guanine and has a double-stranded structure

Question 48

Which of the following is NOT a function of RNA?

Accepted Answer

Storage of genetic information

Answer

Regulation of gene expression

Answer

Catalysis of reactions

Answer

Protein synthesis

Question 49

The genetic code is:

Accepted Answer

Degenerate, meaning multiple codons can code for the same amino acid

Answer

Universal, meaning the same codon codes for the same amino acid in all organisms

Answer

Ambiguous, meaning some amino acids are coded by multiple codons

Question 50

Which of the following techniques uses restriction enzymes to cut DNA at specific recognition sequences?

Accepted Answer

Restriction digestion

Answer

Southern blotting

Answer

Gel electrophoresis

Answer

Polymerase chain reaction

Question 51

Nucleic acids are essential for:

Accepted Answer

Storing and transmitting genetic information

Answer

Providing energy for the cell

Answer

Catalyzing chemical reactions

Answer

Transporting molecules across the cell membrane