Basic Concepts
In a nutshell: DNA is the blueprint of life, and genes are its instructions.
## What is DNA?
DNA (Deoxyribonucleic Acid) is the molecule that contains the instructions an organism needs to develop, live, and reproduce. It's like a recipe book for building a living thing!
- DNA is made up of four chemical bases: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).
- The sequence of these bases forms genes, which are specific instructions for making proteins.
## Genes: The Instructions for Life
Genes are sections of DNA that code for proteins. These proteins perform most life functions and make up the majority of cellular structures.
- Humans have about 20,000-25,000 genes!
- Genes are inherited from our parents, which is why we often resemble them.
## How Does DNA Work?
DNA has a double helix structure. Each base pairs with a partner (A with T, C with G), creating the famous twisted ladder shape.
## Why is DNA Important?
DNA is the foundation of genetics. Understanding it helps us explore how traits are passed from parents to offspring and how variations arise.
### Fun Fact
If you stretched out all the DNA in your body, it would reach from the Earth to the Sun and back—over 600 times!
Examples
- A child inherits brown eyes from one parent and curly hair from another due to specific genes.
- Genetic disorders like cystic fibrosis are caused by mutations in certain genes.
Key terms
- Gene
- A segment of DNA that codes for a specific protein.
- DNA
- The molecule that carries genetic information in living organisms.
- Mutation
- A change in the DNA sequence, which can lead to variation.