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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Some nucleotide sequences are unimportant.
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They are never passed on to the offspring.
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More than one nucleotide sequence may code for the same amino acid.
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They only affect males.
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Detailed explanation-1: -It may result in a synonymous change, the new codon specifying the same amino acid as the unmutated codon. A synonymous change is therefore a silent mutation because it has no effect on the coding function of the genome: the mutated gene codes for exactly the same protein as the unmutated gene.
Detailed explanation-2: -Some mutations don’t have any noticeable effect on the organism. This can happen in many situations: perhaps the mutation occurs in a stretch of DNA with no function, or perhaps the mutation occurs in a protein-coding region, but does not affect the amino acid sequence of the protein.
Detailed explanation-3: -While mutations always change the DNA sequence, they do not always cause a change in the resulting protein or an obvious effect on the organism. This can occur because most amino acids can be coded by two or more different codons.
Detailed explanation-4: -Even though an nucleotide sequence is changed, it does not alter the amino acid of the polypeptide, this is because silent mutation only occurs in the third base of codons as genetic code is degenerate. As silent mutations do not affect the function of the protein, it is considered as a neutral mutation.
Detailed explanation-5: -Mutations can result in a different amino acid sequence in the encoded polypeptide. Some gene mutations change only one triplet code. Due to the degenerate nature of the genetic code, not all such mutations result in a change to the encoded amino acid.