1. What is a Gene? Gene = _______________________________
_______________________________________
Humans have approximately ____________ genes
We have _____ copies of
each gene (one on each chromosome
we inherited from our ___________).
Each gene has different forms . . .
Allele - __________________________________
__________________________________________

2. Examples of Genes and Alleles in Pea Plants
Gene – Seed Shape
Alleles: _____________
_____________
Gene – seed color
Gene – flower color

3. Chromosomes occur in pairs because offspring inherit one from each parent
*We have 46 Chromosomes
(23 pairs of chromosomes)
Chromosomes are made of genes
Circle one gene.
What are the 2 alleles for that gene?
*Each chromosome is made up of ________ that contains hundreds to thousands of __________.
*HIERARCHY:

4. Dominant vs. Recessive NOT ALL ALLELES ARE EXPRESSED
Some alleles are dominant, while others are recessive
Description
More Info
Examples
Dominant
Alleles
*These usually code for a protein so they are the “normal” form of a gene.
Recessive
*These usually code for a different protein, or deactivate the “normal” protein.

5. What happens when we change our DNA?
Mutations: ____________________________
_______________________________________
Gene Mutations: _______________________
Types: _________________________________
Chromosomal Mutations: ________________
 THESE CHANGES CAN AFFECT _________ MADE AND THEREFORE AFFECT YOUR ______________.

6. TYPES OF CHROMOSOMES Autosomes: ___________________________
Sex Chromosomes: ______________________
Karyotype: ____________________________
_______________________________________
Where do you look
To determine the
sex of this human?
How do you know
If it is normal
or abnormal?

7. Karyotype Notation:

8. Significance of Mutations
What Causes Mutations?
There are two ways in which DNA can become mutated:
1. Mutations can be _________.
Parent to child
2. Mutations can be _________.
Environmental damage
Mistakes when DNA is copied
________________failure of chromosomes to separate properly during Meiosis.
What phase normally causes this?
1. MOST ARE _____________
Eye color
Birth marks
2. SOME are _____________
Sickle Cell Anemia
Down Syndrome
3. SOME are _____________
Sickle Cell Anemia to Malaria
Immunity to HIV

9. PRACTICE WITH KARYOTYPES

10. MORE PRACTICE . . .