MCQ - Practice Test -Chapter 5 -Molecular Basis Of Inheritance

Welcome to your Ncert-Class12- Biology- Molecular Basis of inheritance

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Total Questions : 20

Total Marks : 20 x 4 = 80 Marks

Each Correct Question carries : 4 Marks

Each incorrect Question Carries : -1 Marks

Each Unattempted Question carry : 0 Marks

Be careful On Negative Markings

During autocatalysis of DNA, which one of the following provide free OH group and is also used to anchor for addition of new DNA nucleotides?

DNA polymerase

Ligase

RNA primer

Topoisomerase

Analysis of DNA of an organism revealed the following characters. Mark the option that is not likely to be true if the organism is a cat.

The double helix is antiparallel & a linear molecule

20 bases comprising of a mixture of deoxyribonucleotide phosphates (dNTPs) were found in a single 360 degree turn of helix

17 % of the nitrogenous bases were shown to be cysteines

Uracil was lacking but guanine was 17 %

Choose the correct answer from the alternatives given :

Watson and Crick (1953) proposed DNA double helix model and won the Nobel Prize; their model of DNA was based on

(i) X-ray diffraction studies of DNA done by Wilkins and Franklin

(ii) Chargaffs base equivalence rule

(iii) Griffiths transformation experiment

(iv) Meselson and Stahls experiment.

(i), (ii) and (iv)

(i) and (ii)

(iii) and (iv)

(i), (ii), (iii) and (iv)

Choose the correct answer from the alternatives given :

Which of the following phenomena was experimentally proved by Meselson and Stahl?

Transformation

Transduction

Semi-conservative DNA replication

Central dogma

Choose the correct answer from the alternatives given :

Read the following statements.

(i) One codon codes for only one amino acid.

(ii) Some amino acids are coded by more than one codon.

(iii) The, sequence of triplet nitrogenous bases in DNA or mRNA corresponds to the amino acid sequence in the polypeptide chain.

Give suitable terms for the characteristics of genetic code as per the above statements.

Degeneracy - (i), Colinearity - (ii), Unambiguous - (iii)

Degeneracy - (iii) , Colinearity - (ii) , Unambiguous - (i)

Degeneracy - (ii) , Colinearity - (iii) , Unambiguous - (i)

Degeneracy - (i) , Colinearity (ii) , Unambiguous - (iii)

What is the relationship between the nucleotide triplets and the amino acids called?

Genetic code

Transcription

Translation

Replication

Which of the following statements about DNA replication is not correct?

Unwinding of the DNA molecule occurs as hydrogen bonds break

Replication occurs as each base is paired with another exactly like it

Process is known as semiconservative replication because one old strand is conserved in the new molecule

Complementary base pairs are held together with hydrogen bonds

A naturally occurring coding strand composed of alternating C and U residues would result in the formation of

A polypeptide containing alternating leu and ser residues

A polypeptide containing either leu or ser residues

A polypeptide containing only leu residues

A polypeptide containing only ser residues

The double helical model of the DNA was proposed by Watson and Crick based on that what data produced by Wilkins and Franklin?

Hybridization

DNA sequencing

Southern blotting

X-ray diffraction

Which one of the following is correct?

Introns are present in mRNA and exons are present in tRNA.

Codons are present in mRNA and anticodons in tRNA.

Every intron is a set of three terminator codons.

Exons are present in eukaryotes while introns are present in prokaryotes.

Identify the correct and incorrect statements.

A. The four nucleotide bases are not necessarily present in DNA in exact equal proportions.

B. The total amount of purines are equal to the total amount of pyrimidines.

C. DNA ligase enzyme act to hydrolyse or breakdown a polynucleotide chain into its component nucleotides.

D. Nuclease enzymes are capable of restoring an intact DNA duplex.

B is correct but A, C and D are wrong.

A and B are wrong but C and D are correct.

A, B and C are correct but D is wrong.

A and B are correct but C and D are wrong.

The base sequence for a nucleic acid segment is given CAG, AGG, CGA, CCA. From this, it can definitely be concluded that it is a segment of which strand?

DNA strand

mRNA strand

tRNA strand

Data not sufficient

In prokaryotes, the process of replication is catalysed by the following enzymes. Identify which of the enzymes is best coordinated with the role?

Helicase → → Joins the ends of DNA segments

DNA polymerase I → → Synthesis of DNA

DNA polymerase II → → Erases primer and fills gaps

Primase → → Synthesis RNA primers4

The characteristics of a molecular probe are

(I) Very long molecule

(II) Double stranded

(III) DNA or RNA

(IV) Complementary to a part of desired gene

The correct options are

I, II

II, III

III, IV

IV, I

A DNA molecule in which both strand have radioactive thymidine is allowed to duplicate in an environment containing non-radioactive thymidine. What will be the correct number of DNA molecules that contain some radioactive thymidine after three duplications?

There will be four such molecules.

There will be eight such molecules.

There will be only one such molecule.

There will be two such molecules.

What is antisense technology?

When a piece of RNA that is complementary in sequence is used to stop expression of a specific gene

RNA polymerase producing DNA

A cell displaying a foreign antigen used for synthesis of antigens

Production of somaclonal variants in tissue cultures

The sequencing of the entire genome (the totality of all genes) of an organism was completed in 1996. The organism was

Human being

Yeast

Albino mouse

Plasmodium vivax

Choose the correct answer from the alternatives given :

In a DNA strand the nucleotides are linked together by

Glycosidic bonds

Phosphodiester bonds

Peptide bonds

Hydrogen bonds

Which of the following biologists has been dubbed as the architect of molecular biology?

Francis Crick

Frederick Sanger

Jacques Lucien Monod

James Watson

The toxin produced by the bacteria that is responsible for the development of diarrhea is produced by a section of DNA that has the code CCT TAT CAG. The sequence of amino acids produced by this sequence is ____________.

Glycine - isoleucine - aspartic acid

Glycine - isoleucine - valine

Glycine - tyrosine - valine

Glycine - tyrosine - isoleucine

Chapter 4 Principles of Inheritance and Variation

Chapter 5 -Molecular Basis Of Inheritance

Chapter 6- Evolution

Instruction

Curriculum

Ncert -Class 12 - unit VII - GENETICS AND EVOLUTION

Chapter 4 Principles of Inheritance and Variation

Chapter 5 -Molecular Basis Of Inheritance

Chapter 6- Evolution

MCQ – Practice Test -Chapter 5 -Molecular Basis Of Inheritance

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