1. Reproduction and Meiosis
Making gametes…

2. Remember: CHARACTERISTICS OF LIVING THINGS ALL LIVING THINGS __________
REPRODUCE
Planaria animation: Family

3. Two Types of Reproduction
Asexual: Reproduction NOT involving the union of sex cells; 1 parent
Sexual: Reproduction involving sex cells; 2 parents

4. ASEXUAL REPRODUCTION BINARY FISSION
1 parent cell splits into two cells (Through mitosis!) Example: Bacteria

5. Budding ASEXUAL REPRODUCTION
Offspring grows out of the body of the parent Example: Hydra (plant)

6. ASEXUAL REPRODUCTION Regeneration
If a piece of a parent is detached, it can grow and develop into a completely new individual Example: Starfish

7. All 3 Types: Produce cells that are __________ copies of parent cell
identical

8. ADVANTAGES OF ASEXUAL REPRODUCTION
Can make offspring faster
Don’t need a partner

9. DISADVANTAGES OF ASEXUAL REPRODUCTION
ALL ALIKE
Species CAN’T change and adapt
One disease can wipe out whole population

10. SEXUAL REPRODUCTION DIFFERENT Combines genetic material
Family image from:
Combines genetic material
from 2 parents (sperm & egg)
so offspring are
genetically __________
from parents
DIFFERENT

11. ADVANTAGES OF SEXUAL REPRODUCTION
Allows for variation in population
Individuals can be different
Provides foundation for EVOLUTION
Allow species to adapt to
changes in
their environment

12. + 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!

13. MEIOSIS is the way… to make cells with ½ the number of chromosomes
for sexual
reproduction

14. DIPLOID & HAPLOID HOMOLOGOUS CHROMOSOMES
Most cells have 2 copies of each chromosome =
(one from mom; one from dad)
All BODY (___________) cells are diploid
DIPLOID 2n
HOMOLOGOUS CHROMOSOMES
SOMATIC

15. Created through: MITOSIS
Makes ___ cells genetically _________ to parent cell & to each other
Used by organisms to: repair injuries, increase size of organism, replace worn out cells 2
identical

16. DIPLOID & HAPLOID
Some cells have only one copy of each chromosome = _____________
All sperm and egg cells
are haploid
HAPLOID 1n

17. Created through MEIOSIS4
Makes ____ cells genetically different from parent cell & from each other
Sex cells are called ________ cells or Germ Cells
Used in _____
Gamete
sexual reproduction

18. MAKING SPERM & EGGS

19. If you are female:
Produce 1 Egg, 3 Polar Bodies The cytoplasm divides unevenly resulting in 1 good egg and the 3 smaller bodies which are consumed by the lysosmes

20. If you are male:
Meiosis produces 4 sperm cells

21. Development of a Baby
1 sperm + 1 egg = fertilization = conception Conception  Zygote  Fetus  Baby

22. MITOSIS vs MEIOSIS INTERPHASE INTERPHASE I
DNA Replicates
Cell Grows
SAME AS
MITOSIS

23. MITOSIS vs MEIOSIS PROPHASE PROPHASE I
Chromosomes form Nuclear membrane disappears Centrioles/spindle fibers appear
Chromosomes form
Nuclear membrane disappears
Centrioles/ spindle fibers appear
Homologous pairs match up

24. Homologous Chromosomes
Match up forming a Tetrad
(4 sets of sister chromatids)
Crossing over occurs

25. CROSSING OVER

26. MITOSIS vs MEIOSIS METAPHASE METAPHASE I
with homologous partner
Animation
Chromosomes line up in middle
Spindle fibers attach to center
Chromosomes line up in middle (along equator)
Spindle fibers attach to center

27. INDEPENDENT ASSORTMENT

28. MITOSIS vs MEIOSIS ANAPHASE ANAPHASE I
Chromatids split
Chromatids stay together Homologous pairs split
(segregation)

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

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

31. 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

32. MITOSIS vs MEIOSIS PROPHASE PROPHASE II
DNA condenses into chromosomes
Nuclear membrane/ nucleolus disappear
Centrioles/ spindle fibers appear
SAME AS MITOSIS

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

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

35. MITOSIS vs MEIOSIS TELOPHASE TELOPHASE II
Two nuclei
Nuclear membrane/ nucleolus returns
Centrioles/spindle fibers disappear
DNA spreads out as chromatin
SAME AS MITOSIS

36. MITOSIS vs MEIOSIS CYTOKINESIS CYTOKINESIS II
SAME AS MITOSIS
Cytoplasm splits

37. End result of meiosis: 4 haploid cells with 23 chromosomes
We look different from our family members because of
Genetic Recombination:
Crossing over
Independent Assortment