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C-value is the characteristic DNA content in a haploid cell of a given species. Earlier it was considered that C-value correlates with organism complexity. However, it is now evident that C-value varies enormously among species and that this bears no correlation with the complexity of the organisms. For example, the cells of some salamanders may contain 40 times more DNA than those of humans. Which of the following explains this C-value paradox?

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Important Questions on Molecular Basis of Inheritance

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The DNA fingerprinting analysis of four family members is shown below.

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Study the band pattern obtained and assign each family member to W, X, Y and Z. Choose the correct option.

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An organism uses 20 amino acids while its DNA is made up of 6 types of nitrogenous bases. What would be the minimum size of a codon?
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The semi-conservative nature of DNA replication was established by Meselson and Stahl in their classic experiment with bacteria. They grew bacteria in N15. NH4Cl containing medium, washed and then incubated in fresh medium with N14- containing compounds and allowed to grow for three generations. CsCl density gradient centrifugation of isolated DNA established the nature of semiconservative DNA replication. The pictorial representation below shows the position of differentially labeled DNA in CsCl density gradient.

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Had the DNA replication been conservative, what would have been the pattern?

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You have created a fusion between trp operon and lac operon, which encodes the enzymes for tryptophan biosynthesis under the regulatory control of the lac operator. Under which of the following conditions will tryptophan synthase be induced in the strain that carries the chimeric operator fused operons?
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A DNA sequence undergoes three subsequent point mutations which result in subsequent changes in transcription of mRNA as shown below:
Original mRNA  :AUG  CAU  CUC  ACG  GAU  UAG

Point mutation 1 : AUG CAU CUU ACG GUA UAG

Point mutation 2 : AUG CAU GCU UAC GGU AUA

Point mutation 3 : AUG CAU GCU UAA GGU AUA

Select the correct sequence of point mutations that occurred in the DNA.

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In a DNA strand the nucleotides are linked together by ----------------.
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A nucleoside differs from a nucleotide. It lacks ----------------.
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Both deoxyribose and ribose belong to a class of sugars called -------------.