1. 1.2 DNA & Genes Inside the Nucleus
The nucleus of every cell contains chromosomes
These act like a master set of instructions called that determines what each cell will become, how it will function, and how long it will live before being replaced.
Chromosomes carry this information made of DNA (DeoxyriboNucleic Acid).

2. Chromosomes carry this information made of DNA
Every species have pairs of chromosomes (one from Mom, one from Dad)
Humans have 46 chromosomes
23 from Mom
23 from Dad

3. Karyotype of a Human Male

4. DNA Every chromosome is made of one molecule of DNA
DNA is divided into many genes that control protein production
1953 Watson & Crick founded the DNA model we use today
the double helix
DNA

5. Each DNA molecule is made with building blocks of 4 types:
Adenine pairs with Thymine
Cytosine pairs with Guanine
it’s in the gene sequence that we get differences among individuals
hair colour, how tall you are, allergies…

6. Mutations
a change in an organisms DNA where the order of the A,T,C,G has been altered so proteins may not be able to do their job correctly
Ex. Sickle cell anemia where the blood loses ability to bind oxygen
Caused by mutagens (substance or factor that causes mutation in DNA) like x-rays, UV rays from sun, tar in cigarettes
Some mutagens affect one cell, many cells, or can be inherited
Some mutagens are not harmful at all as they may not target the coded part of genes
Gene therapy (correcting faulty genes) is ongoing research to help fix these problems and decrease disease