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Why do some DNA mutations have no obvious effect?
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heredity
Each offspring is a combination of its two parents, receiving some dominant traits from its mother and others from its father.
DNA mutations often have no obvious effect because many are classified as silent mutations. This occurs for several reasons:12
- Redundancy of the Genetic Code: The genetic code is redundant, meaning multiple codons can code for the same amino acid. A mutation may change a DNA sequence without altering the resulting amino acid in the protein chain.34
- Similar Properties: In some cases, a mutation results in a different amino acid, but that new amino acid happens to have the same chemical properties as the original, allowing the protein to maintain its function.14
- Location: Many mutations occur in non-coding regions of the DNA located between genes, where they do not interfere with protein synthesis or gene regulation.2
- Masking in Diploid Organisms: In diploid organisms, a recessive mutation may be masked by a functional wild type allele on the homologous chromosome, preventing the mutant phenotype from being expressed.4