THE MOLECULAR BASIS OF INHERITANCE
DNA REPLICATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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a free phosphate group attached to the 3’ carbon of its deoxyribose sugar
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a hydroxyl group (OH) attached to the 3’ carbon of its deoxyribose sugar
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a free phosphate group attached to the 5’ carbon of its deoxyribose sugar
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a hydroxyl group (OH) attached to the 5’ carbon of its deoxyribose sugar
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Detailed explanation-1: -The phosphate group is attached to the 5′ carbon of one nucleotide and the 3′ carbon of the next nucleotide. In its natural state, each DNA molecule is actually composed of two single strands held together along their length with hydrogen bonds between the bases.
Detailed explanation-2: -The 5’ end of a single DNA strand contains a free phosphate, while the 3’ end contains a free OH.
Detailed explanation-3: -The correct answer is true. The statement is valid because, in every nucleotide structure, a phosphate group is linked to the fifth carbon of the sugar unit. This sugar is either a deoxyribose sugar or ribose sugar.
Detailed explanation-4: -DNA and RNA are composed of nucleotides that are linked to one another in a chain by chemical bonds, called ester bonds, between the sugar base of one nucleotide and the phosphate group of the adjacent nucleotide. The sugar is the 3’ end, and the phosphate is the 5’ end of each nucleiotide.
Detailed explanation-5: -DNA is made of two linked strands that wind around each other to resemble a twisted ladder-a shape known as a double helix. Each strand has a backbone made of alternating sugar (deoxyribose) and phosphate groups. Attached to each sugar is one of four bases: adenine (A), cytosine (C), guanine (G) or thymine (T).