1.2 The Nucleus and DNA
All About the Nucleus
What is DNA?
It's time to take a closer look at what's inside the nucleus-the nucleolus and the cell's DNA.
DNA stands for “deoxyribonucleic acid.” It is a code containing about three billion (that's 3 000 000 000!) bases. |
The Most Famous Molecule
DNA is the chemical that carries genetic information from parents to offspring. Although DNA consists of very long strands of bases, there are only four types of bases. This means that the sequence in which they are strung together is very important.
This sequence of bases leads to the creation of proteins. In turn, those proteins determine the characteristics of an organism. Your unique DNA sequence, and the proteins it codes for, makes you different from all other forms of life on earth.
DNA molecules
The DNA molecule is a 'double helix' because it is made of two strands that wind around each other like ribbons. Bonding between base pairs connects these strands.
The structure of DNA itself is too small to see under a microscope, but it's easy to extract the larger 'strings' into which it is organized.