1. Elodea Cells 400x Magnification
cell wall
cytoplasm
nucleus
Elodea Cells x Magnification

2. It all starts in the nucleus
Introduction to Genes
It all starts in the nucleus
How do cells know what to do and how does a single cell become a full grown multicellular plant or animal?

3. How do your cells know what to do?

4. NUCLEUS Found in both plant and animal cells
Control Center of the cell. “Brain” of the cell.
Directs all of the cells activities
But how?

5. DNA (found in the nucleus)

6. In most plant and animal cells, chromosomes come in pairs
Instructions for determining cell structure and function are found in chromosomes inside the nucleus of the cell
In most plant and animal cells, chromosomes come in pairs
One from each parent
Humans usually have 46 chromosomes in 23 pairs
What about other species?

7. CHROMOSOMES Organism # of chromosomes per cell Humans 46 Cow 60
Chicken 78
Corn 20
Butterfly 80
Fruit Fly 8

8. CHROMOSOMES
Karyotype

9. DNA: Deoxyribonucleic acid
Chromosomes are made of DNA
DNA forms a long winding shape called a helix. This helix has two main strands, so it is a double helix.

10. DNA: Deoxyribonucleic acid
Scientists James Watson and Francis Crick created the double helix model that we know today
DNA is made up of building block molecules represented by the letters A (adenine), T (thymine), G (guanine) and C (cystine)
The order of these building blocks is what makes up our genetic code

11. GENES DNA contains segments called genes
Most genes provide the cell with instructions for making proteins (using a code)
This code consists of sequences of A, T, G and C
Thus, genes control the cell’s activities and much of it’s structure

12. FROM GENES TO PROTEINS The Code: A always pairs with T
C always pairs with G
Each DNA molecule contains hundreds or thousands of genes
Genes control many features such as hair and eye colour, food allergies, height
Genes determine what kinds of proteins your cells can make which determines how your body functions and/or looks
Environmental factors can play a role as well

13. Each protein is designed to carry out a specific job
FROM GENES TO PROTEINS
Each protein is designed to carry out a specific job
Some examples include:
Building parts of the body
Couriers to carry materials throughout the body
Transfer signals within the body
Speed up chemical reactions within the body