1. Variation
Objective 2

2. Sexual Reproduction
Asexual reproduction is when one organism makes a copy of itself
Cells (mitosis)
Sex is an improvement of asexual reproduction
Largest source of variation of life
Scrambles the genes of two different organisms of the same species

3. Review
Why is sex important?

4. Crossing Over
Why do brothers/sisters not look identical if they are made from the same 2 parents?
Crossing over is how your genes scramble together to make each egg/sperm unique from the others

5. Crossing Over
In prophase 1 the chromosomes line up next to each other making a unique shape (tetrad)

6. Crossing Over
While in tetrads the chromosomes will swap massive pieces of DNA
Draw this step

7. Crossing Over
While in tetrads the chromosomes will swap massive pieces of DNA
Draw this step

8. Review
What is the name of the shape chromosomes form during prophase I of meiosis?
What happens to the DNA in the chromosomes while they are crossed over each other?

9. Mutation Mutation is a change in the genetic code
Mutations are the original source of all variety on the planet
Mutations fall into 2 categories
Gene mutations
Chromosome mutations

10. Review What is the original source of all variation on the planet?
What is a mutation?
What are the two categories of mutation?

11. Gene Mutations Frameshift Mutations
The gene is lengthened or shortened
Deletion
Insertion
Deletion
Insertion

12. Gene Mutations Point Mutations Mutations at a single point in a gene
Substitution
Insertion
Deletion
Deletion
Substitution
Insertion

13. Chromosome Mutations Changes at the chromosome level
Many genes can be affected
Deletion
Duplication
Inversion
Translocation
Deletion
Duplication
Inversion
Translocation

14. Review What are the two types of Gene Mutation?
Which type of mutation effects the most genes?
What is the original source of all variation?
What is the largest source of all variation?