OBJECTIVE LIFE SCIENCE
BIOCHEMISTRY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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DNA cannot be repaired and this explains why mutations occur.
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Specific enzymes bind the correct nucleotides.
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The new nucleotides basepair accurately with those on the complementary strand.
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The repair enzyme recognizes the removed nucleotide and brings in an identical one to replace it.
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The three-dimensional structure determines the order of nucleotides.
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Detailed explanation-1: -Incorrectly paired nucleotides cause deformities in the secondary structure of the final DNA molecule. During mismatch repair, enzymes recognize and fix these deformities by removing the incorrectly paired nucleotide and replacing it with the correct nucleotide.
Detailed explanation-2: -Base pairing ensures that the sequence of nucleotides in the existing template strand is exactly matched to a complementary sequence in the new strand, also known as the anti-sequence of the template strand.
Detailed explanation-3: -In excision repair, the damaged DNA is recognized and removed, either as free bases or as nucleotides. The resulting gap is then filled in by synthesis of a new DNA strand, using the undamaged complementary strand as a template.
Detailed explanation-4: -This process is called proofreading. If the polymerase detects that a wrong (incorrectly paired) nucleotide has been added, it will remove and replace the nucleotide right away, before continuing with DNA synthesis 1 ^1 1start superscript, 1, end superscript.
Detailed explanation-5: -More broadly, RADAR-seq provides a comprehensive understanding of the damage potential of metabolic processes, environmental factors and chemotherapies and can be utilized to understand DNA replication and repair mechanisms.