Understanding DNA Mutations: Types and Causes

Mutation

Permanent change in an organism's genetic material.

Somatic Cells

Non-reproductive cells; mutations not inherited.

Germ Cells

Reproductive cells; mutations passed to offspring.

Point Mutations

Affects one or few nucleotides in DNA.

Substitution Mutation

One nucleotide replaced by another.

Insertion Mutation

An extra base is added to DNA.

Deletion Mutation

A base is missing from DNA sequence.

Missense Mutation

Results in an altered protein function.

Silent Mutation

No effect on cell's metabolism or function.

Nonsense Mutation

Gene cannot code for a functional polypeptide.

Frameshift Mutation

Caused by insertions or deletions, altering reading frame.

Spontaneous Mutations

Occur naturally, often due to DNA replication errors.

Induced Mutations

Caused by external factors like mutagens.

Physical Mutagens

Cause breaks in nucleotide sequences (e.g., X-Rays).

Chemical Mutagens

React chemically with DNA, causing permanent changes.

Carcinogenic Mutagens

Mutagens that can cause cancer in organisms.

Beneficial Mutation

Rarely advantageous, can increase genetic variability.