Mutations occur when mistakes are made during transcription or replication of DNA. There are several kinds of mutations that occur in organisms. Mutations usually happen when chromosomes break or when nucleotides on a chromosome are changed, inserted, or deleted. Everyone has mutations, and most mutations are harmless. However, there are some mutations that can lead to serious illness or death.
Mutation: A change in the bases of DNA/RNA.
Mutagen: Something that causes mutation.
Germline Mutation: A mutation in a gamete (can be passed onto offspring).
Somatic Mutation: Mutation that occurs in a somatic (non-gamete) cell.
Chromosomal Alteration: Mutation that changes chromosome structure.
Point Mutation: One nucleotide is changed.
Frameshift Mutation: When a nucleotide is deleted or inserted.
Genetic Disorder: Disease caused by gene mutations.
Most mutations are accidental and happen randomly as the result of mistakes during DNA replication or transcription
Mutations affect the genetic material. The effect can be a chromosomal alteration, point mutation, or frameshift mutation.
Chromosomal alterations happen when part of a chromosome breaks off and doesn't rejoin correctly.
Point mutations tend to be less serious, but the effect depends on how the mutation changes the genetic code.
Types of point mutations:
Frameshift mutations can greatly affect protein synthesis. Since codons are groups of 3nucleotides, adding/deleting a nucleotide shifts everything over and changes every codon afterwards, which completely changes the amino acids produced.
Now, assume an insertion occurs in this sequence. Let’s say a C nucleotide is inserted after the start codon AUG:
The amino acid sequence changed dramatically even though only one nucleotide was inserted.