1. Eukaryotic Life Cycles BIOL 1407

2. Life Cycles Asexual Reproduction Sexual Reproduction –Gametic meiosis –Zygotic meiosis –Alternation of Generations

3. Asexual Reproduction Watch Video #4, binary fission in Paramecium http://www.microscopyu.com/moviegallery/pondscum/protozoa/paramecium/t1/paramecium04.html Photo Credit: Courtesy of Richard Allen @ http://www5.pbrc.hawaii.edu/allen/http://www5.pbrc.hawaii.edu/allen/

4. Gametic Meiosis Diploid multicellular organism Produces gametes by meiosis Gametes = only haploid stage

5. Gametic Meiosis Gametes always fuse to form zygote Zygote grows into diploid multicellular organism

6. Zygotic Meiosis Haploid multicellular organism Produces gametes by mitosis Gametes always fuse to form zygote

7. Zygotic Meiosis Zygote  meiosis  haploid spores Zygote = only diploid stage Spores grow into haploid multicellular organisms

8. Alternation of Generations Two generations: –Multicellular haploid organism –Multicellular diploid organism –Life cycle alternates between the two

9. Alternation of Generations Multicellular diploid organism Produces haploid spores by meiosis

10. Alternation of Generations Spores grow into haploid multicellular organisms Haploid multicellular organism produces gametes by mitosis

11. Alternation of Generations Gametes always fuse to form zygote Zygote grows into diploid multicellular organism

13. Question: Which Type?

14. The End Unless otherwise specified, all images in this presentation came from: Campbell, et al. 2008. Biology, 8 th ed. Pearson Benjamin Cummings.