Frame shift mutation:
**Frame Shift Mutation**
**Core Concept**
A frameshift mutation is a type of genetic mutation caused by insertions or deletions of nucleotides in a DNA sequence, resulting in a change in the reading frame of the genetic code. This disruption in the sequence leads to the synthesis of a completely different protein or a nonfunctional protein.
**Why the Correct Answer is Right**
Frameshift mutations occur due to insertions or deletions of nucleotides, which alter the reading frame of the genetic code. As a result, the sequence of amino acids in the protein is changed, often leading to a nonfunctional or dysfunctional protein. This type of mutation can occur in any gene and can have significant effects on the organism's phenotype.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not describe a frameshift mutation. A point mutation involves a change in a single nucleotide, whereas a frameshift mutation involves the insertion or deletion of nucleotides.
**Option B:** This option is incorrect as it describes a chromosomal mutation, not a frameshift mutation. Chromosomal mutations involve changes in the number or structure of chromosomes.
**Option C:** This option is incorrect as it describes a silent mutation, not a frameshift mutation. A silent mutation is a type of point mutation where the change in the nucleotide sequence does not result in a change in the amino acid sequence.
**Clinical Pearl / High-Yield Fact**
Frameshift mutations are often caused by errors during DNA replication or repair and can be induced by mutagenic chemicals or radiation. These mutations can have significant effects on the organism's phenotype and are often associated with genetic disorders.
**Correct Answer: D. Frameshift mutation is a type of genetic mutation caused by insertions or deletions of nucleotides in a DNA sequence, resulting in a change in the reading frame of the genetic code.**