DNA, RNA and Experiments on Genetic Material, Class 12 Biology NCERT Solutions

1. There will be total 20 MCQ in this test.
2. Please keep a pen and paper ready for rough work but keep your books away.
3. The test will consist of only objective type multiple choice questions requiring students to mouse-click their correct choice of the options against the related question number.
4. No negative marking for incorrect choice.
5. Please click on “Finish the Test” when you want to exit.
6. All the best – Happy Studying

1. Who among the following scientists had no contribution in the development of the double helix model for the structure of DNA?

  Meselson and Stahl

 Rosalind Franklin

 Erwin Chargaff

 Maurice Wilkins

Question 1 of 20

2. DNA has genetic properties was revealed for the first time by

 Chargaff

 Griffith

 Avery

 Wilkins

Question 2 of 20

3. The beginning of understanding genetic transformation in bacteria was made by

 Hershey and Chase

 Watson and Crick

 Frederick Griffith

 T. H. Morgan

Question 3 of 20

4. DNA contains nucleobases, sugar and phosphate. Removal of which among these from a DNA sample will not significantly affect the length of DNA?

  Nucleobases

  Sugar

 Phosphate

 None of the above

Question 4 of 20

5. According to Chargaff’s rule, which one is correct?

  [A] + [T] = [G] + [C]

 [A] + [C] = [G] + [T]

  [A] + [G] = [T] + [C]

 All of these

Question 5 of 20

6. Whose experiments cracked the DNA and discovered unequivocally that a genetic code is a triplet?

 Nirenberg and Matthaei

 Hershey and Chase

  Beadle and Tatum

 Morgan and Sturtevant

Question 6 of 20

7. In Hershey and Chase experiments, radioactive ³²P was used to culture bacteriophages which resulted in radioactive

  Protein capsule of bacteriophage

 Viral DNA

 Bacterial capsule

 Viral proteins

Question 7 of 20

8. Which of the following is a structural subunit of DNA?

 Nucleotides

 Carbohydrate

 Protein

 RNA

Question 8 of 20

9. Which of the following are the functions of RNA?

 It is a carrier of genetic information from DNA to ribosomes synthesising polypeptides.

 It carries amino acids to ribosomes.

 It is a constituent component of ribosomes.

 All of the above.

Question 9 of 20

10. While analysing the DNA of an organism, a total number of 5386 nucleotides were found out of which the proportion of different bases were Adenine = 29%, Guanine = 17%, Cytosine = 32% and Thymine = 17%. Considering the Chargaff’s rule, it can be concluded that

 It is a double-stranded linear DNA.

 It is single-stranded DNA.

 No conclusion can be drawn.

 It is a double-stranded circular DNA.

Question 10 of 20

11. Nitrogenous bases present in DNA:

 Adenine, guanine, cytosine, thymine

  Guanine, uracil

  Adenine, guanine, cytosine, uracil

 Adenine, thymine, uracil

Question 11 of 20

12. Beadle and Tatum showed that each kind of mutant bread mould they studied lacked a specific enzyme. Their experiments demonstrated that

 Genes carry information for making proteins.

 Enzymes are required to repair damage.

  Cells need specific enzymes in order to function.

 Genes are made up of DNA.

Question 12 of 20

13. A typical nucleosome contains

 100 bp of DNA helix

 400 bp of DNA helix

 200 bp of DNA helix

 300 bp of DNA helix

Question 13 of 20

14. DNA nucleotides are attached by

 Van der Waals bond

 Electrovalent bond

 Hydrogen bond

 Covalent bond

Question 14 of 20

15. In the DNA molecule,

 There are two strands which run parallel in the 5′-3′ direction.

 The total amount of purine nucleotides and pyrimidine nucleotides is not always equal.

 Proportion of adenine in relation to thymine varies with the organism.

 There are two strands which run antiparallel – one in 5′-3′ direction and other in 3′-5′ direction.

Question 15 of 20

16. Retroviruses have genetic material

 DNA only

 Either DNA or RNA only

 DNA or RNA only

 RNA only

Question 16 of 20

17. If the percentage of cytosine is 18%, then the percentage of adenine will be

 64%

 32%

 23%

 36%

Question 17 of 20

18. Uracil is present in RNA at the place of

 Adenine

 Thymine

  Guanine

 Cytosine

Question 18 of 20

19. The genetic material of a viroid is

 Protein

 DNA

 Carbohydrate

 RNA

Question 19 of 20

20. The net electric charge on DNA and histones is

 Negative and positive, respectively

 Both negative

 Both positive

 Zero

Question 20 of 20

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