MCQ ON DNA class 12 for NEET

MCQ ON DNA class 12 for NEET | THE DNA class 12 | MCQ DNA with Answer | Check the below NCERT MCQ question for class 12 Biology chapter 06 based on the with Answers.

MCQ on DNA class 12 Biology with answers were prepared based on the latest pattern.We have provided class 12 Biology MCQs questions on DNA with Answers to help students understand the concept very well.

MCQ ON DNA is useful for NEET / CSIR / UGC / CBSE / ICSE / AIIMS / EXAM / AFMC EXAM / STATE LEVEL MEDICAL EXAM 2022-23, 2023-24

Introduction:
DNA is a long polymer of deoxyribonucleotides. The length of DNA is usually defined as the number of nucleotides present in it.This also is the characteristics of an organisms.DNA acts as a genetic materials in most of the organisms.

 

MCQ ON DNA class 12 for NEET

1. DNA is a long polymer of ….

(a) ribonucleoside
(b) deoxyribonucleotides
(c) deoxyribonucleosides
(d) ribonucleotide

Ans (b) deoxyribonucleotides

2. The length of DNA is usually defined as

(a) number of nucleosides
(b) number of nucleotides
(c) base pairs
(d) both a and c

Ans. (d) both a and c

3. A bacteriophage lambda has ……….base pairs.

(a) 48502
(b) 48606
(c) 48504
(d) 48509

Ans. (a)48502

4. A nucleotides has three components

(a) a nitrogenous base
(b) a pentose sugar
(c) a phosphate group
(d) all the above

Ans.(d) all the above

5. Purine a nitrogenous base contains

(a) adenine and guanine
(b) thymine and uracil
(c) adenine and thymine
(d) adenine and cytosine

Ans.(a) adenine and guanine

6. Pyramidines a nitrogenous base is made of

(a) cytosine
(b) uracil
(c) thymine
(d) all the above

Ans.(d) all the above

7. Common to both DNA and RNA is

(a) uracil
(b) thymine
(c) cytosine
(d) guanine

Ans.(c) cytosine

8. A Thymine is present in

(a) DNA only
(b) RNA only
(c) both DNA and RNA
(d) none of the above

Ans.(a) DNA only

9. Uracil is present in RNA in the place of

(a) cytosine
(b) thymine
(c) guanine
(d) adenine

Ans. (b) thymine

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10. The backbone of a polynucleotide chain is formed due to

(a) sugar
(b) phosphates
(c) both a and b
(d) nitrogenous

Ans. (c) both a and b

11. DNA is ……. substance.

(a) basic
(b) acidic
(c) neutral
(d) none of the above

Ans.(b) acidic

12. DNA is an acidic substance present in nucleus was first identified by

(a) Mendel
(b) Robert brown
(c) Friedrich Meischer
(d) Watson

Ans . (c) Friedrich Meischer

13. Double helix model of DNA was given by

(a) James Watson and Francis Crick
(b) Robert hook and Robert brown
(c) Wilkins and Franklin
(d) Mendel and Vries

Ans.(a) James Watson and Francis Crick

15. Double helix model of DNA was given based on

(a) MRI
(b) X- ray diffraction data
(c) CT scan
(d) PET scan

Ans. (b) X-ray diffraction data

16.In DNA ,the ratio between Adenine and Thymine and Guanine and Cytosine are constant and equal to …

(a) 0
(b) less than 1
(c) more than a
(d) equal to 1

Ans.(d) equal to 1

17. A very unique property to the polynucleotide chains

(a) base pairing
(b) adenine and guanine
(c) cytosine and uracil
(d) RNA

Ans.(a) base pairing

18. Adenine forms……. hydrogen bonds with Thymine

(a) two
(b) three
(c) four
(d) five

And.(a) two

19. Guanine is bonded with Cytosine with ………..bonds.

(a) two
(b) three
(c) four
(d) five

Ans. (b) three

20. The pitch of the DNA helix is

(a) 3.4 nm
(b) 0.34 nm
(c) 34 nm
(d) 34.4 nm

Ans.(a) 3.4 nm

21.The distances between a base pairs in a helix is approximately

(a) 0.34 nm
(b) 3.4 nm
(c) 0.034 nm
(d) 0.00034 nm

Ans. (a) 0.34 nm