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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Half of each new DNA is the old DNA
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The old strand of DNA was digested, so none
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The new DNA is entirely made up of the old DNA
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About every sixth base comes from the old DNA
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Detailed explanation-1: -The result of DNA replication is two DNA molecules consisting of one new and one old chain of nucleotides. This is why DNA replication is described as semi-conservative, half of the chain is part of the original DNA molecule, half is brand new.
Detailed explanation-2: -The percentage of adenine will equal the percentage of thymine, and the percentage of cytosine will equal the percentage of guanine. Together, these percentages will add to 100%. We know that the sample is 35% adenine, which tells us that it is also 35% thymine.
Detailed explanation-3: -The initiation of DNA replication occurs in two steps. First, a so-called initiator protein unwinds a short stretch of the DNA double helix. Then, a protein known as helicase attaches to and breaks apart the hydrogen bonds between the bases on the DNA strands, thereby pulling apart the two strands.
Detailed explanation-4: -Each strand of DNA acts as a template for synthesis of a new, complementary strand. Replication produces two identical DNA double helices, each with one new and one old strand.