Eukaryotic Life Cycles BIOL 1407 Life Cycles Asexual

Eukaryotic Life Cycles BIOL 1407

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

Asexual Reproduction • Watch Video #4, binary fission in Paramecium • • http: //www. microscopyu. com/moviegallery/pondscum/protozoa/paramecium/t 1/paramecium 04. html Photo Credit: Courtesy of Richard Allen @ http: //www 5. pbrc. hawaii. edu/allen/

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

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

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

Zygotic Meiosis • Zygote meiosis haploid spores • Zygote = only diploid stage • Spores grow into haploid multicellular organisms

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

Alternation of Generations • Multicellular diploid organism • Produces haploid spores by meiosis

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

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

Question: Which Type?

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