DNA (Deoxyribonucleic Acid)
What is DNA?
DNA is the genetic material found in almost all living organisms
It carries the instructions that tell cells how to grow, function, and reproduce
Where is DNA found?
Mainly in the nucleus of a cell
A small amount is also found in mitochondria
Structure of DNA
Shaped like a double helix (twisted ladder)
Made of two strands
The sides are sugar and phosphate
The rungs are base pairs:
A (Adenine) pairs with T (Thymine)
G (Guanine) pairs with C (Cytosine)
What does DNA do?
Controls growth and development
Decides physical features (eye colour, height, etc.)
Helps make proteins needed by the body
Passes traits from parents to offspring
DNA, Genes, and Chromosomes
Gene: A small section of DNA with a specific instruction
Chromosome: A tightly coiled DNA structure containing many genes
Why is DNA important?
Makes every organism unique
Essential for inheritance, evolution, and life itself