CELL STRUCTURES AND FUNCTION
BIO MOLECULES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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3.4 nm
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0.34 nm
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34 nm
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0.034 nm
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Detailed explanation-1: -Final answer: Each base pair is 0.34nm away from the next one in a double helix DNA.
Detailed explanation-2: -In an experiment, DNA is treated with a compound which tends to place itself amongst the stacks of nitrogenous base pairs. As a result of this, the distance between two consecutive bases increases, from 0.34 nm to 0.44 nm.
Detailed explanation-3: -Thus, the correct answer is (B)-2.2meters.
Detailed explanation-4: -The diameter of the B-DNA is 20 Angstroms, and the distance between base pairs is 3.4 Angstroms. The base pairing of opposite strands is stereochemically selective, Adenine always pairing with Thymine, and Guanine with Cytosine.
Detailed explanation-5: -The DNA double helix biopolymer of nucleic acid is held together by nucleotides which base pair together. In B-DNA, the most common double helical structure found in nature, the double helix is right-handed with about 10–10.5 base pairs per turn.