THE MOLECULAR BASIS OF INHERITANCE
STRUCTURE OF NUCLEIC ACIDS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The phosphodiester bond protects the chemical reactive bases
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the pentose sugar
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the three hydrogen bonds between C and G
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The two hydrogen bonds between A and T
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The bonds between the bases
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Detailed explanation-1: -The structure of the DNA helix is stabilized by van der Waals forces, hydrogen bonds between complementary organic bases (a base pair), and hydrophobic interactions between the nitrogenous bases and the surrounding sheath of water.
Detailed explanation-2: -In addition to holding the DNA strands together, the hydrogen bonding between the complementary bases also sequester the bases in the interior of the double helix. Therefore, the hydrogen bonding between the bases reinforces the hydrophobic effects that stabilize the DNA.
Detailed explanation-3: -From the base-pairing diagram, we can see that the G-C pair has 3 hydrogen bonds, while the A-T pair has only 2. Therefore, the G-C pairing is more stable than the A-T pairing. Thus, strands with more G-C content have more hydrogen bonding, are more stable, and have a greater resistance to denaturation.
Detailed explanation-4: -Two factors are mainly responsible for the stability of the DNA double helix: base pairing between complementary strands and stacking between adjacent bases.