MCQ on DNA with Answers: 

• Nucleic acid is a biological macromolecular compound composed of many nucleotides and is one of the most basic substances of life.
• There are two types of nucleic acid DNA and RNA.
• DNA is the carrier of all genetic information. 
• DNA is a macromolecular polymer composed of deoxynucleotides.
• Deoxynucleotides are composed of bases, deoxyribose sugars, and phosphates.
• There are four bases: adenine (A), guanine (G), thymine (T), and cytosine (C).
• The diameter of the helix is ​​2 nm; the helix period contains 10 pairs of bases; the pitch of the helix is ​​3.4 nm; the distance between the planes of adjacent base pairs is 0.34 nm.
• The DNA molecule is a double helix structure formed by two anti-parallel long chains of deoxynucleotides.
• The deoxyribose and phosphate in the DNA molecule are alternately connected and arranged on the outside to form the basic skeleton; the bases are arranged on the inside.
• Base pairings are always A with T and G with C. Base pairs are held together by hydrogen bonds, two hydrogen bonds are formed between A and T, and three hydrogen bonds are formed between G and C. 
• DNA carries The genetic information necessary for the synthesis of RNA and proteins is essential for the development and normal functioning of organisms.”

DNA MCQ with Answers Pdf : 

1. Who discovered DNA?

(1) Friedrich Miescher

(2) James Watson

(3) Francis Crick

(4) Altman

Answer: 1

2. The basic unit of DNA molecule is_______

(1) Deoxyribonucleotides

(2) ribonucleotides

(3) Nitrogenous bases

(4) Gene

Answer: 1

3. The double helix structure of DNA was discovered by_____

(1) Friedrich Miescher

(2) James Watson

(3) Francis Crick

(4) Both (2) and (3)

Answer: 4

4. Which is the monomer of DNA?

(1) Deoxyribonucleotides

(2) ribonucleotides

(3) Nitrogenous bases

(4) Gene

Answer: 1

5. What is the full form of DNA?

(1) Degenerative acid

(2) Deoxyribonucleic acid

(3) Deadly nucleic acid

(4) Disoriented acid

Answer: 2

6. What is the most common form of DNA?

(1) B-form

(2) Z-form

(3) B-form

(4) None of these

Answer: 1

7. Compared to RNA, the unique components of DNA are

(1) Ribose and uracil

(2) Deoxyribose and thymine

(3) Deoxyribose and uracil

(4) Deoxyribose and Guanine

Answer: 2

8. The following substances that can polymerize to form DNA molecules are________

(1) Deoxyribose

(2) deoxynucleotides

(3) amino acid

(4) nitrogenous base

Answer: 2

9. What is the backbone of DNA?

(1) ​Phosphate Backbone

(2) Sugar Backbone

(3) Adenine Backbone

(4) Both (2) and (3)

Answer: 1

10. DNA in human epithelial cells is present in________

(1) Nucleus, chloroplasts, mitochondria

(2) nucleus, mitochondria

(3) nucleus

(4) nucleus, ribosome, mitochondria

Answer: 2

11. What is the shape of DNA?

(1) The double helix

(2) Triple helix

(3) Both

(4) None of these

Answer: 1

12. If the DNA strand has nitrogenous base sequence ATT GCC, the mRNA will have?

(1) ATTGCA

(2) UGGACC

(3) UAACGG

(4) ATCGCC

Answer: 3

13. DNA in wheat root tip present in________

(1) The nucleus, chloroplast, and Golgi

(2) Endoplasmic reticulum, mitochondria, and nucleus

(3) Mitochondria, chloroplasts, and nucleus

(4) nucleus, mitochondria

Answer: 4

14. A group of the following structures all containing DNA is_________

(1) Chloroplast, Golgi, centrosome, chromosome

(2) Chloroplasts, mitochondria, nucleus, bacterial plasmids

(3) Endoplasmic reticulum, ribosome, nucleus, centrosome

(4) Mitochondria, Ribosomes, Chromosomes, Golgi Apparatus

Answer: 2

15. Which of the following is not a correct statement concerning DNA?

(1) It is a long polymer

(2) It is found in the nucleus

(3) It is a basic substance

(4) First identified by Friedrich Meischer

Answer: 3

16. Which of the following is a component of DNA

(1) Deoxyribose, nucleic acid, and phosphate

(2) Deoxyribose, base, and phosphate

(3) Ribose, base, and phosphate

(4) Nucleosides, bases, and phosphates

Answer: 2

17. The substance that can be obtained after complete hydrolysis of DNA is_______

(1) amino acid

(2) Amino acids and deoxynucleotides

(3) Carbon dioxide, water, and N-containing wastes

(4) Deoxyribose, N-containing bases, and phosphates

Answer: 4

18. Which of the following statements about the basic functions of DNA is incorrect

(1) Genetic information is stored in DNA

(2) DNA transfers genetic information through replication

(3) DNA is the embodiment of biological traits

(4) DNA expresses genetic information through transcription and translation

Answer: 3

19. By which of the following bonds, a nitrogenous base is linked to pentose sugar?

(1) Phosphate bond

(2) Ester bond

(3) Peptide bond

(4) N-glycosidic bonds

Answer: 4

20. Which of the following statements about DNA is false

(1) DNA in the nucleus of various somatic cells of the same organism has the same base composition

(2) The base content of a double-stranded DNA molecule is A+G=C+T or A+C=G+T

(3) The base content of a double-stranded DNA molecule is A/T=G/C

(4) DNA is only found in the nucleus

Answer: 4

21. This force can stabilize a DNA double-helix__________

(1) Hydrophilic sugar-phosphate groups are found on the exterior of the helix where interaction with water occurs

(2) Hydrophobic bases are present in the interior of the helix, each base pair is stabilized by the same number of hydrogen bonds

(3) covalent base stacking interactions may take place between neighboring bases within the same strand in the helix

(4) non-covalent N-glycosidic bonds may form between nitrogenous bases in opposite strands in the helix

Answer: 1

22. In this type of DNA replication, of the two newly formed molecules, one is purely a new one and the other is an old one_______

(1) dispersive

(2) conservative

(3) semiconservative

(4) both (2) and (3)

Answer: 3

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