THE MOLECULAR BASIS OF INHERITANCE
DNA MAKES RNA MAKES PROTEIN
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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They change every codon after the mutation.
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They can be passed on to offspring.
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They always cause some form of cancer.
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The mutation only occurs at one point in the DNA.
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Detailed explanation-1: -Because an insertion or deletion results in a frame-shift that changes the reading of subsequent codons and, therefore, alters the entire amino acid sequence that follows the mutation, insertions and deletions are usually more harmful than a substitution in which only a single amino acid is altered.
Detailed explanation-2: -Insertion and deletion mutations can have more devastating effects on encoded proteins because, unlike point mutations that can cause a single amino acid in a protein to be changed or cause a protein to be shortened, insertions and deletions have the potential to cause frameshift mutations.
Detailed explanation-3: -Why? Frameshift mutations are more detrimental to the cells because it usually changes 2 amino acids, whereas point mutations only change 1.
Detailed explanation-4: -In case of deletion or insertion of a particular fragment of the gene, deletion could be more harmful than insertion, because the deleted fragment of the gene will never be replaced at exact size and exact position of the disabled gene.
Detailed explanation-5: -However, base substitutions do not always cause a change in the sequence of amino acids. This is due to the degeneracy in the genetic code; the fact that there are 64 different possible triplets but only 20 different amino acids, some must code for the same amino acid.