Molecular Basis...

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion : The uptake of DNA during transformation is an active, energy requiring process.

Reason : Transformation occurs in only those bacteria, which possess the enzymatic machinery involved in the active uptake and recombination.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion : Adenine and guanine are double - ring bases.

Reason: Adenine and guanine are pyrimidines.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion: Sequences of bases in one polynucleotide chain of DNA can determine the sequence of bases in the other chain.

Reason: In a DNA, amount of adenine equals that of thymine and amount of guanine equals that of cytosine, i.e., A = T and C = G.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion: The concept of one gene-one enzyme was changed to one gene-one polypeptide.

Reason : Each enzyme may consist of two or more different polypeptides.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion : /RNA acts as an adapter molecule.

Reason : /RNA recognizes codon sequence of mRNA during translation.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion : Same /RNA can recognise more than one codon differing only at the third position.

Reason : The specificity of a codon is particularly determined by the first two bases.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion: Initiation step of protein synthesis in prokaryotes and eukaryotes has several differences. Reason: They both form mRNA - /RNA complexes with smaller subunits of ribosome.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion : Ribosomes attached to endoplasmic reticulum release proteins into lumen of ER.

Reason : Such proteins are used for formation of hydrolytic enzymes or are modified.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion: R-type of Pneumococcus is non-virulent.

Reason : R-type of Pneumococcus can be virulent by having transformation with S - type of Pneumococcus.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion: B-DNA has a constant diameter of 20 A.

Reason : A pyrimidine always pairs with a purine.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion : Z-DNA follows a zig-zag course.

Reason : Z-DNA is left handed.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion: Core enzyme catalyses chain elongation of RNA.

Reason : The presence of sigma factor is required for initiation of transcription.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion : The genetic code is degenerate.

Reason : For a particular amino acid more than one codon can be used.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion; The subunits of ribosomes come together only at the time of protein formation.

Reason : Mg2t causes their association or dissociation.

Directions: Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

Assertion : UAA, UAG and UGA terminate protein synthesis.

Reason: They are not recognised by /RNA.