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 two strands are running in the same direction.
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The two strands are not complimentary to each other.
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One strand is running in one direction (2’ to 3’) and the other strand is running in the other direction (3’ to 2’).
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One strand is running in one direction (5’ to 3’) and the other strand is running in the other direction (3’ to 5’).
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Detailed explanation-1: -The strands of a DNA double helix are said to be “antiparallel” because the have the same chemical structure, but are opposite in direction.
Detailed explanation-2: -Each end of DNA molecule has a number. One end is referred to as 5’ (five prime) and the other end is referred to as 3’ (three prime). The 5’ and 3’ designations refer to the number of carbon atom in a deoxyribose sugar molecule to which a phosphate group bonds.
Detailed explanation-3: -If the DNA strand was parallel, replication would not be possible. The nucleotides would not be complementary to each other and, as a result, would not pair in a genetic molecule. Therefore, the DNA being antiparallel is the only way replication and life could occur.
Detailed explanation-4: -The double helix describes the appearance of double-stranded DNA, which is composed of two linear strands that run opposite to each other, or anti-parallel, and twist together. Each DNA strand within the double helix is a long, linear molecule made of smaller units called nucleotides that form a chain.