1. MEIOSIS Chapter 11-4 Making reproductive cells …. called the gametes
Making reproductive cells …. called the gametes

2. + EGG SPERM  If egg and sperm had same number of
Image by Riedell
Image by Riedell
EGG +
SPERM 
If egg and sperm had same number of
chromosomes as other body cells . . .
baby would have too many chromosomes!

3. is a special type of cell division…
- makes cells with half number of chromosomes
for sexual
reproduction

4. A. DIPLOID & HAPLOID -called homologous chromosomes
- most cells have 2 copies of each chromosome = diploid (2n)
(one from mom; one from dad)
- all body or somatic cells are diploid.
-called homologous chromosomes

5. - some cells have only one copy of each chromosome = haploid (1n)
- all sperm and egg cells
are haploid.

6. B. MEIOSIS Makes 4 cells genetically different from parent cell
Makes haploid gamete cells
Main cause of genetic variation in individuals
reshuffles genes during process
Used for sexual reproduction

7. MITOSIS vs MEIOSIS INTERPHASE INTERPHASE I
DNA is spread out as chromatin
Nuclear membrane/ nucleolus visible
DNA is copied during S phase
Makes ‘stuff’ new cell needs in G2
SAME AS
MITOSIS

8. MITOSIS vs MEIOSIS PROPHASE PROPHASE I
DNA coils into chromosomes Nuclear membrane disappear Spindle fibers appear
DNA coils into chromosomes
Nuclear membrane disappear
Spindle fibers appear
Homologous chromosomes pair up

9. C. WHAT MAKES PROPHASE IN MITOSIS DIFFERENT FROM PROPHASE 1 IN MEIOSIS?
-Exchange of DNA between homologous pairs = CROSSING-OVER during PROPHASE I
-allows shuffling of the genetic
material of DNA
-creates genetic variation

10. SEE CROSSING OVER ANIMATION
Video 5
Crossing Over
SEE CROSSING OVER ANIMATION
Video 5

11. MITOSIS vs MEIOSIS METAPHASE METAPHASE I
Chromosomes line up in middle
Chromosomes line up in middle
with homologous pair

12. MITOSIS vs MEIOSIS ANAPHASE ANAPHASE I
APART:
APART:
Chromatids split
Chromatids stay together; Homologous pairs split

13. MITOSIS vs MEIOSIS TELOPHASE TELOPHASE I
See TWO nuclei
Nuclear membrane returns
DNA spreads out as chromatin
Spindle/centrioles disappear
SAME AS MITOSIS

14. MITOSIS vs MEIOSIS CYTOKINESIS CYTOKINESIS I
Cytoplasm splits
into 2 cells
SAME AS
MITOSIS

15. MITOSIS vs MEIOSIS INTERPHASE II
DNA is spread out as chromatin
Nuclear membrane/ nucleolus visible
DNA is copied during S phase
SKIP
INTERPHASE II
DNA NOT COPIED

16. MITOSIS vs MEIOSIS PROPHASE PROPHASE II
DNA scrunches into chromosomes
Nuclear membrane disappear
Spindle fibers appear
SAME AS MITOSIS

17. MITOSIS vs MEIOSIS METAPHASE METAPHASE II
Chromosomes line up in middle
SAME AS MITOSIS

18. MITOSIS vs MEIOSIS ANAPHASE ANAPHASE II
Chromatids split and move apart
SAME AS MITOSIS

19. MITOSIS vs MEIOSIS TELOPHASE TELOPHASE II
Two nuclei
Nuclear membrane/ nucleolus returns
Centrioles/spindle fibers disappear
DNA spreads out as
chromatin
SAME AS MITOSIS
Cells contain single copy of each gene

20. MITOSIS vs MEIOSIS CYTOKINESIS CYTOKINESIS II
Produces 4 haploid cells,
results in egg or sperm cells
Cytoplasm splits, producing 2 diploid cells