Class 12 Biology - Chapter 6: Molecular Basis of Inheritance MCQ Questions

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Question 1

Which of the following steps in transcription is catalysed by RNA polymerase?

A All of the above.

B Termination

C Elongation

D Initiation

Question 2

Which was the last human chromosome to be completely sequenced :

A Chromosome X.

B Chromosome 21

C Chromosome 11

D Chromosome 1

Question 3

The human chromosome with the highest and least number of genes in them are respectively:

A Chromosome X and Y.

B Chromosome 1 and Y

C Chromosome 1 and X

D Chromosome 21 and Y

Question 4

Control of gene expression takes place at the level of:

A None of the above

B Translation

C Transcription

D DNA-replication

Question 5

With regard to mature mRNA in eukaryotes:

A both exons and introns appear in the mature RNA.

B introns appear but exons do not appear in the mature RNA

C exons appear but introns do not appear in the mature RNA

D exons and introns do not appear in the mature RNA

Question 6

Which of the following statements is the most appropriate for sickle cell anaemia?

A All of the above.

B It confers resistance of acquiring malaria.

C It is a molecular disease.

D It cannot be treated with iron supplements.

Question 7

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

A Meselson and Stahl.

B Erwin Chargaff

C Maurice Wilkins

D Rosalind Franklin

Question 8

Who proved semiconservative mode of DNA replication for the first time in E. coli with the help of N¹⁵ heavy nitrogen isotope?

A Luria and Delbruck

B Messelson and Stahl

C Kornberg and Ochova

D Watson and Crick

Question 9

The first genetic material could be :

A RNA.

B DNA

C carbohydrates

D protein

Question 10

DNA is a polymer of nucleotides which are linked to each other by 3â€™-5â€™ phosphodiester bond. To prevent polymerisation of nucleotides, which of the following modifications would you choose?

A Both â€˜Bâ€™ and â€˜Câ€™.

B Remove/Replace 2â€™ OH group with some other group in deoxyribose

C Remove/Replace 3â€™ OH group in deoxyribose

D Replace purine with pyrimidines

Question 11

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%, Thymine = 17%. Considering the Chargaffâ€™s rule it can be concluded that:

A No conclusion can be drawn.

B It is a double-stranded linear DNA.

C It is a single-stranded DNA.

D It is a double-stranded circular DNA.

Question 12

A nucleoside differs from a nucleotide. It lacks the :

A hydroxyl group.

B phosphate group

C sugar

D base

Question 13

The net electric charge on DNA and histones is :

A zero

B negative and positive, respectively

C both negative

D both positive

Question 14

Regulatory proteins are the accessory proteins that interact with RNA polymerase and affect its role in transcription. Which of the following statements is correct about regulatory protein?

A They can act both as activators and as repressors.

B They interact with RNA polymerase but do not affect the expression.

C They only decrease expression.

D They only increase expression.

Question 15

Both deoxyribose and ribose belong to a class of sugars called :

A polysaccharides.

B pentoses

C hexoses

D trioses

Question 16

One of the following is true with respect to AUG

A All of the above.

B It codes for methionine in both prokaryotes and eukaryotes.

C It is also an initiation codon.

D It codes for methionine only.

Question 17

The promoter site and the terminator site for transcription are located at:

A the 3â€™ (downstream) end.

B the 5â€™ (upstream) end

C 5â€™ (upstream) end and 3â€™ (downstream) end, respectively of the transcription unit

D 3â€™ (downstream) end and 5â€™ (upstream) end, respectively of the transcription unit

Question 18

Which of the following are the functions of RNA ?

A All of the above.

B It is a constituent component of ribosomes.

C It carries amino acids to ribosomes.

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

Question 19

The fact that a purine base always paired through hydrogen bonds with a pyrimidine base leads to, in the DNA double helix :

A uniform length in all DNA.

B uniform width throughout DNA

C the semiconservative nature

D the antiparallel nature

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Class 12 Biology - Chapter 6: Molecular Basis of Inheritance MCQ Questions

Your Class 12 Biology Study Path

Which of the following steps in transcription is catalysed by RNA polymerase?

Which was the last human chromosome to be completely sequenced :

The human chromosome with the highest and least number of genes in them are respectively:

Control of gene expression takes place at the level of:

With regard to mature mRNA in eukaryotes:

Which of the following statements is the most appropriate for sickle cell anaemia?

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

Who proved semiconservative mode of DNA replication for the first time in E. coli with the help of N¹⁵ heavy nitrogen isotope?

The first genetic material could be :

DNA is a polymer of nucleotides which are linked to each other by 3â€™-5â€™ phosphodiester bond. To prevent polymerisation of nucleotides, which of the following modifications would you choose?

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%, Thymine = 17%. Considering the Chargaffâ€™s rule it can be concluded that:

A nucleoside differs from a nucleotide. It lacks the :

The net electric charge on DNA and histones is :

Regulatory proteins are the accessory proteins that interact with RNA polymerase and affect its role in transcription. Which of the following statements is correct about regulatory protein?

Both deoxyribose and ribose belong to a class of sugars called :

One of the following is true with respect to AUG

The promoter site and the terminator site for transcription are located at:

Which of the following are the functions of RNA ?

The fact that a purine base always paired through hydrogen bonds with a pyrimidine base leads to, in the DNA double helix :

Practice Complete!

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Class 12 Biology - Chapter 6: Molecular Basis of Inheritance MCQ Questions

Your Class 12 Biology Study Path

Which of the following steps in transcription is catalysed by RNA polymerase?

Which was the last human chromosome to be completely sequenced :

The human chromosome with the highest and least number of genes in them are respectively:

Control of gene expression takes place at the level of:

With regard to mature mRNA in eukaryotes:

Which of the following statements is the most appropriate for sickle cell anaemia?

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

Who proved semiconservative mode of DNA replication for the first time in E. coli with the help of N15 heavy nitrogen isotope?

The first genetic material could be :

DNA is a polymer of nucleotides which are linked to each other by 3â€™-5â€™ phosphodiester bond. To prevent polymerisation of nucleotides, which of the following modifications would you choose?

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%, Thymine = 17%. Considering the Chargaffâ€™s rule it can be concluded that:

A nucleoside differs from a nucleotide. It lacks the :

The net electric charge on DNA and histones is :

Regulatory proteins are the accessory proteins that interact with RNA polymerase and affect its role in transcription. Which of the following statements is correct about regulatory protein?

Both deoxyribose and ribose belong to a class of sugars called :

One of the following is true with respect to AUG

The promoter site and the terminator site for transcription are located at:

Which of the following are the functions of RNA ?

The fact that a purine base always paired through hydrogen bonds with a pyrimidine base leads to, in the DNA double helix :

Practice Complete!

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Percentage Calculator

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What Students Are Viewing

Who proved semiconservative mode of DNA replication for the first time in E. coli with the help of N¹⁵ heavy nitrogen isotope?