DNA Mutations - Biology

1. Fundamental Concepts

Definition: DNA mutations are changes in the DNA sequence that can alter genetic information.
Types of Mutations: Point mutations, insertions, deletions, and chromosomal mutations.
Impact on Organisms: Mutations can be beneficial, neutral, or harmful, depending on their effect on the organism's phenotype.

Point Mutations: $A \rightarrow G$ (Substitution)

Insertions and Deletions: $ATCG \rightarrow AT\text{---}CG$ (Insertion) or $ATCG \rightarrow A\text{---}G$ (Deletion)

Chromosomal Mutations: $46 \rightarrow 45$ (Monosomy) or $46 \rightarrow 47$ (Trisomy)

Problem: Identify the type of mutation in the following DNA sequence change: $ATCG \rightarrow ATAG$

Validation: The change involves a single nucleotide substitution, confirming it is a point mutation.

Problem: Determine the type of mutation in the following DNA sequence change: $ATCG \rightarrow AT\text{---}CG$

Validation: The addition of a new nucleotide confirms it is an insertion mutation.

Sequence Comparison: Align the original and mutated sequences to identify changes.
Mutation Type Identification: Use the following criteria:
- Point Mutation: Single nucleotide change (substitution)
- Insertion: Addition of one or more nucleotides
- Deletion: Removal of one or more nucleotides
- Chromosomal Mutation: Changes in the number or structure of chromosomes
Contextual Analysis: Consider the impact of the mutation on the organism's phenotype and function.