GENETICS AND EVOLUTION
MOLECULAR BASIS OF INHERITANCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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two, two
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three, three
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two, three
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three, two
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Detailed explanation-1: -Adenine forms two hydrogen bonds with Thymine from oposite strand and vice-versa. Similarly, guanine is bonded with Cytosine with three H-bonds. As a result, always a purine comes opposite to a pyrimidine. This generates approximately uniform distance between the two strands of the helix.
Detailed explanation-2: -Adenine always pairs with thymine through two hydrogen bonds in DNA. Similarly, adenine pairs with uracil through two hydrogen bonds in RNA and guanine always pairs with cytosine through three hydrogen bonds in both the nucleic acids.
Detailed explanation-3: -Guanine binds with cytosine in DNA and RNA and forms three hydrogen bonds. This occurs because guanine has two nitrogen atoms and one oxygen atom that are able to form hydrogen bonds, so three bonds occur between these bases.
Detailed explanation-4: -DNA. In the DNA helix, the bases: adenine, cytosine, thymine and guanine are each linked with their complementary base by hydrogen bonding. Adenine pairs with thymine with 2 hydrogen bonds. Guanine pairs with cytosine with 3 hydrogen bonds.
Detailed explanation-5: -The Adenine-Thymine base pair is held together by 2 hydrogen bonds while the Guanine-Cytosine base pair is held together by 3 hydrogen bonds. That is also the reason why the two strands of a DNA molecule can be separated more easily at sections that are densely populated by A-T base pairs.