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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copying of chromosomes only occurs during the S phase of the cell cycle
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Cell will not enter the mitotic phase unless all the DNA has replicated
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chromosomes must be attached to the mitotic spindle for mitosis to complete
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checkpoints in the system include proteins called cyclins and enzymes called cyclin-dependent kinases (Cdks)
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cells must be large enough, and enough proteins and nucleotides must be present
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Detailed explanation-1: -Two key structural features of eukaryotic DNA that are different from prokaryotic DNA are the presence of histone complexes and telomere structures. Histones are responsible for the structural organization of DNA in eukaryotic chromosomes.
Detailed explanation-2: -DNA replication takes place during the Synthesis (S) phase of cell cycle. During S phase, an enzyme called helicase unwinds the DNA strand. The two single DNA strands can then be used as templates to form two identical double DNA strands.
Detailed explanation-3: -The mechanism of eukaryotic DNA replication is similar to that of prokaryotic DNA replication. However, eukaryotic DNA replication requires special consideration due to differences in DNA sizes, unique linear DNA end structures called telomeres, and distinctive DNA packaging that involves complexes with histones.
Detailed explanation-4: -There are four basic components required to initiate and propagate DNA synthesis. They are: substrates, template, primer and enzymes.