genetic variation

Your genetic information is stored in Deoxyribonucleic Acid, or DNA. It's a molecule famous for its double helix shape, like a twisted ladder. Each side of this ladder is a strand made of repeating units called nucleotides.

Each nucleotide has three parts:
1. A deoxyribose sugar (the "D" in DNA).
2. A phosphate group.
3. A nitrogenous base.

Your body is made of trillions of cells, all originating from a single fertilized egg. This incredible growth and constant maintenance depend on cell division. There are two main types: mitosis and meiosis. Both involve copying DNA, but their purposes and outcomes are very different.

• Point Mutations: These are changes at a single nucleotide base.
  • Substitution: One base is swapped for another (e.g., A for G). This can be silent (no change in protein), missense (changes one amino acid), or nonsense (creates a premature stop codon).
  • Insertion/Deletion (Indel): Adding or removing one or more nucleotides. If it's not a multiple of three, it causes a frameshift mutation, completely changing the downstream protein sequence.