Components of DNA: Building Blocks of Life

Question 1

Which of the following nitrogenous bases is NOT present in DNA?

Accepted Answer

Uracil

Answer

Adenine

Answer

Cytosine

Answer

Thymine

Question 2

Which of the following is **not** a building block of a nucleotide found in DNA?

Accepted Answer

Amino acid

Answer

Deoxyribose sugar

Answer

Phosphate group

Answer

Nitrogenous base

Question 3

Which type of bond connects adjacent nucleotides in a DNA molecule, forming the backbone?

Accepted Answer

Phosphodiester bond

Answer

Peptide bond

Answer

Glycosidic bond

Answer

Hydrogen bond

Question 4

What is the characteristic three-dimensional shape of a DNA molecule?

Accepted Answer

Double helix

Answer

Triple helix

Answer

Linear chain

Answer

Branched chain

Question 5

Which of the following statements about DNA is accurate?

Accepted Answer

DNA has the ability to replicate itself.

Answer

A DNA molecule consists of only one strand.

Answer

DNA contains uracil instead of thymine.

Answer

DNA is found exclusively in the nucleus of eukaryotic cells.

Question 6

Which base is complementary to adenine in DNA?

Accepted Answer

Thymine

Answer

Guanine

Answer

Cytosine

Answer

Uracil

Question 7

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

Accepted Answer

Helicase

Answer

Ligase

Answer

Polymerase

Answer

Transcriptase

Question 8

What is the process by which the genetic information in DNA is utilized to direct the synthesis of proteins?

Accepted Answer

Translation

Answer

Transcription

Answer

Replication

Answer

Mutation

Question 9

How does complementary base pairing contribute to the accuracy of DNA replication?

Accepted Answer

It ensures that each new DNA strand has bases that match the bases on the original strand, leading to accurate replication of genetic information.

Answer

It allows DNA replication to occur in both directions on the template strand.

Answer

It provides the energy needed for DNA replication.

Answer

It completely prevents the formation of incorrect base pairs during replication.

Question 10

Identify the component that is NOT present in a nucleotide.

Accepted Answer

Ribose sugar

Answer

Nitrogenous base

Answer

Deoxyribose sugar

Answer

Phosphate group

Question 11

In DNA, which nitrogenous base pairs with cytosine?

Accepted Answer

Guanine

Answer

Adenine

Answer

Thymine

Answer

Uracil

Question 12

Which sugar molecule is a component of DNA?

Accepted Answer

Deoxyribose

Answer

Glucose

Answer

Ribose

Answer

Fructose

Question 13

What is the primary function of the phosphate group in a DNA molecule?

Accepted Answer

To confer a negative charge

Answer

To protect DNA from damage

Answer

To form bonds with other DNA molecules

Answer

To store genetic information

Question 14

From 5' to 3', what is the correct sequence of DNA components?

Accepted Answer

Sugar-Phosphate-Base

Answer

Phosphate-Base-Sugar

Answer

Sugar-Base-Phosphate

Answer

Base-Sugar-Phosphate

Question 15

Which term describes the distinctive double helix shape of DNA?

Accepted Answer

B-form

Answer

C-form

Answer

Z-form

Answer

A-form

Question 16

Who is credited with unraveling the double helix structure of DNA?

Accepted Answer

James Watson and Francis Crick

Answer

Erwin Chargaff

Answer

Rosalind Franklin and Maurice Wilkins

Answer

Gregor Mendel

Question 17

In DNA replication, what is the primary function of DNA polymerase?

Accepted Answer

To add nucleotides to the growing DNA strand

Answer

To proofread and repair DNA errors

Answer

To attach primers to the DNA template

Answer

To decompose DNA into smaller molecules

Question 18

What process involves copying DNA into RNA?

Accepted Answer

Transcription

Answer

Translation

Answer

Replication

Question 19

Which of the following is NOT a component of a nucleotide found in DNA?

Accepted Answer

Amino acid

Answer

Phosphate group

Answer

Deoxyribose sugar

Answer

Nitrogenous base

Question 20

Which nitrogenous base is complementary to adenine in DNA?

Accepted Answer

Thymine

Answer

Guanine

Answer

Cytosine

Answer

Uracil

Question 21

What type of bond connects the deoxyribose sugars in the DNA backbone?

Accepted Answer

Phosphodiester bond

Answer

Ionic bond

Answer

Hydrogen bond

Answer

Covalent bond

Question 22

What is the primary function of hydrogen bonds in the structure of DNA?

Accepted Answer

Maintain the double helix structure

Answer

Form the covalent bonds in the backbone

Answer

Store genetic information

Answer

Connect nitrogenous bases to the sugar-phosphate backbone

Question 23

Which characteristic is unique to deoxyribose sugar in DNA?

Accepted Answer

Has a single hydroxyl group (-OH) on the 2' carbon

Answer

Is a five-carbon sugar

Answer

Has a double bond between the 2' and 3' carbons

Answer

Is found only in RNA

Question 24

What is the main advantage of the double helix structure of DNA?

Accepted Answer

Provides stability and protects genetic information

Answer

Enhances gene expression

Answer

Allows for easy replication

Question 25

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

Question 26

Which of these is NOT a part of a nucleotide?

Accepted Answer

Ribose sugar

Answer

Deoxyribose sugar

Answer

Phosphate group

Answer

Nitrogenous base

Question 27

What type of sugar is found in DNA?

Accepted Answer

Deoxyribose

Answer

Ribose

Answer

Glucose

Answer

Sucrose

Question 28

What is the main function of the phosphate group in DNA?

Accepted Answer

To link nucleotides together

Answer

To stabilize the DNA helix

Answer

To pair with nitrogenous bases

Answer

To provide energy for DNA replication

Question 29

What is the best description of the shape of a DNA molecule?

Accepted Answer

Double helix

Answer

Triple helix

Answer

Single helix

Answer

Linear chain

Question 30

Which enzyme is primarily responsible for building new DNA strands during replication?

Accepted Answer

DNA polymerase

Answer

RNA polymerase

Answer

Protease

Answer

Kinase

Question 31

What type of mutation involves a change in just one nucleotide?

Accepted Answer

Point mutation

Answer

Deletion mutation

Answer

Inversion mutation

Answer

Frameshift mutation

Question 32

What is the process called where a copy of DNA is made?

Accepted Answer

DNA replication

Answer

Translation

Answer

Transcription

Answer

Recombination

Question 33

Which of these is a key function of DNA in a living organism?

Accepted Answer

Storing genetic information

Answer

Catalysing chemical reactions

Answer

Providing energy

Answer

Transporting substances

Question 34

Which of the following is NOT a component of a nucleotide found in DNA?

Accepted Answer

Amino acid

Answer

Nitrogenous base

Answer

Phosphate group

Answer

Deoxyribose sugar

Question 35

In DNA, adenine (A) always pairs with which nitrogenous base?

Accepted Answer

Thymine (T)

Answer

Uracil (U)

Answer

Cytosine (C)

Answer

Guanine (G)

Question 36

What is the primary function of the deoxyribose sugar in DNA?

Accepted Answer

To form the backbone of the DNA molecule

Answer

To carry the genetic code

Answer

To form hydrogen bonds with the bases

Question 37

Which statement best describes the structure of DNA?

Accepted Answer

A double helix with two strands running in opposite directions

Answer

A triple helix with three strands

Answer

A branched structure with multiple arms

Answer

A single helix with a linear structure

Question 38

The sequence of nitrogenous bases in DNA directly determines:

Accepted Answer

The genetic code

Answer

The shape of the DNA molecule

Answer

The type of sugar present

Answer

The number of nucleotides in a strand

Question 39

What type of bonds hold the nitrogenous bases together in the DNA double helix?

Accepted Answer

Hydrogen bonds

Answer

Ionic bonds

Answer

Covalent bonds

Answer

Van der Waals forces

Question 40

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

Accepted Answer

Uracil (U)

Answer

Adenine (A)

Answer

Guanine (G)

Answer

Cytosine (C)