1. Reproduction and Meiosis
How organisms make new individuals

2. Asexual reproduction
Requires 1 parent, no sexes
Uses mitosis

3. Budding
Multi-cellular offspring grows off of parent
Ex. Hydra

4. Binary Fission
A single cell Protista divides into two cells forming two new organisms by mitosis
Ex. amoeba

5. Sexual Reproduction Requires 2 parents Uses a process called meiosis
Male produces sperm with half the DNA
Female produces eggs with half the DNA
Combined - Sperm and eggs come together to form new individual zygote with whole DNA

6. Fertilization
The combining of the male sperm and the female egg

7. External fertilization
When the fertilization occurs outside of the body. Ex. Male fish releases sperm over female eggs in water – called spawning

8. Internal Fertilization
When fertilization occurs inside the females body
Ex. Human, mammals, reptiles, birds

9. Plant reproduction Also sexual Male and female usually on same plant
Conifers have male and female cones

10. Gametes Male gamete – Sperm Millions produced at one time very small
have a flagella to swim
Produced in Testes
Female gamete – Egg
Only one produced at a time
Very large
free moving
Produced in Ovaries

11. Zygote
When sperm and egg unite, they combine chromosomes for a zygote with 2 sets of chromosomes.
The offspring has a combination of the genetic instructions from both parents

12. v
Haploid = Each gamete has ½ the number of chromosomes of the parents.
Diploid = two sets of chromosome. The normal number
Egg and sperm form a diploid zygote

13. Chromosomes
DNA wound up on histone proteins for sorting during mitosis

14. Karyotype A method of visually organizing an individuals chromosomes
Aids in identifying chromosome abnormalities

15. Autosomes
All the Non sex chromosomes
Humans have 22 autosomes pairs

16. Sex Chromosomes X and Y – Different, not homologous
Determine male or female
Presence of a Y causes development as a male

17. Meiosis Meiosis is the process for the formation of Gametes
Meiosis is similar to mitosis
but there is a second
Complete division
Occurs ONLY in sex organs

19. Gameteogenesis Formation of gametes by meiosis.
In male 4 sperm are produced,
In female only 1 egg and 3 polar bodies are produced

20. Meiosis I First stage of meiosis
Homologous Chromosomes line up and go to separate cells.
Chromatids do NOT split at Centromere

21. Meiosis II Immediately follows telophase I
NO new DNA replication occurs
Each homologue splits at centromere, with only one chromatid to each cell

22.                                    
Prophase I
Chromosomes appear, centrioles, spindle fibers etc

23. Tetrads
The two sets of homologous chromosomes that organize together during prophase I
Provides for crossing over and recombination between homologues

24. Crossing over Occurs during prophase I into metaphase
Homologous Chromosomes switch some pieces (Recombine) between different chromatids to increase genetic diversity
Chisamata – where homologues connect and cross over

25. Metaphase I Chromosome Tetrads line up
NOTE - matching pairs line side by side
(in mitosis, each chromosome is separate)

26. Anaphase I Chromosome PAIRS separate
(In mitosis each chromatid separates from sister)

27. Telophase I 2 cells separate following cytokinesis
Meiosis II IMMEDIATELY follows

28. Prophase II
Each of the 2 cells prepares to divide again

29. Metaphase II
Chromosomes line up along middle

30. Anaphase II
Sister Chromatids separate
                      

31. Telophase II Four haploid daughter cells are produced
Each daughter cell has half the number of chromosomes from the parent cell (haploid)

32. Interesting fact
Because each of the 23 pairs of chromosomes can line up in two different ways one person can produce more than 8 million different kinds of eggs or sperm.  When fertilization occurs,
70 trillion different zygotes are possible!
You are 1 in 70 trillion

33. Meiosis overview

34. Comparison Mitosis Meiosis 1  2 cells 1  4 cells Diploid  diploid
Goe through Once
Homologues line up separately
No crossing over
Chromatids separate during anaphase
Produces identical cells with full DNA
Meiosis
1  4 cells
Diploid  haploid
Goes through Twice
Homologues line up together in tetrads
Crossing over
Chromatids do not separate during anaphase I, only anaphase II
Produces gametes with half DNA

35. Animation of meiosis