1. Chapter 6 Sections 1,2 and 6 Pages 166-176; 189-191
MEIOSIS vs MITOSIS
Chapter 6 Sections 1,2 and 6
Pages ;

3. What are GENES and how do we inherit them from our parents?
Has anyone ever told you that you look like your mom or dad? What about your siblings? This happens due to sexual reproduction and the inheritance of your parents genes using sex cells from MEIOSIS!

4. Important words: Meiosis Genes Gametes Haploid Diploid Crossing over
Independent assortment

5. REVIEW OF MITOSIS Here is what we know about mitosis so far…
Used in eukaryotic cells
Unicellular = asexual reproduction
Multicellular = growth and repair
Creates two genetically IDENTICAL somatic cells
no genetic variation
Body cells (like skin, eyeballs, liver, kidney)
- Duplicates DNA to maintain chromosome number

6. So what is MEIOSIS?
MEIOSIS is like mitosis, but it is the process of creating genetically DIFFERENT cells by creating sex cells (gametes).
Used for sexual reproduction.
Creates four genetically different sex cells!
Genetic variation

7. Meiosis makes sex cells (egg and sperm cells)
MALE
FEMALE

8. Meiosis is needed for sexual reproduction
Sexual reproduction – the combination of two parent cells using gametes (sex cells) to create genetically different offspring!
Like humans and other animals and plants that can reproduce sexually.
*Gamete – sex cells; egg and sperm.
Haploid – one copy of chromosomes (gametes); n
Diploid – two copies of chromosomes. (one from mom and one from dad) ; 2n

9. BODY CELLS (mitosis)
GAMETES (meiosis)

10. Meiosis and DNA Meiosis makes ½ DNA of the parent sex cell!
That way, a sperm cell can combine with an egg cell to form a full set of DNA!
½ DNA from SPERM + ½ DNA from EGG = 1 FULL SET of DNA for OFFSPRING!
Or, ½ set from dad + ½ set from mom = full set for child

13. Compare and Contrast Mitosis and Meiosis
BOTH MITOSIS AND MEOSIS
Eukaryotic organisms
One parent cell
Replicates and splits DNA
MITOSIS VS MEIOSIS
Genetically identical
Body cells (somatic)
Makes full set of parent DNA
*diploid cells (2n)
Takes place all the time
Creates 2 daughter cells
Asexual reproduction
NO crossing over of genes
Genetically different
Sex cells (gametes)
Makes ½ of parent cell DNA
*haploid cells (n)
Takes place only certain times in life
Creates 4 daughter cells
Sexual reproduction
Crossing over of genes

14. How do we get genetic variation?
Crossing over – this is where some genes will cross over to another chromatid to “change up” the genetic code.

15. How do we get genetic variation?
Independent Assortment – different traits are inherited separately. - the presence of one trait doesn’t affect another - discovered by Gregor Mendel WHY DO CHROMOSOMES INDEPENDENTLY ASSORT AND NOT GENES?

16. Genes cross over
4 new cells!
(egg or sperm)

18. GROUP PROJECT
PART 2:
(Page 2) Draw what happens in MITOSIS when your organisms needs to repair and replace its SOMATIC body cells.
Be specific with chromosome numbers and stages
Show the separation into diploid cells.
(Page 3) Draw what happens in MEIOSIS when your organism creates GAMETES. Begin with the correct amount of chromosomes.
Show the first separation of cells and the crossing over of genes in color pencil
Show the second separation of cells into haploid cells.