1. Life Cycles Laboratory
Observations of Life Cycle Stages in Protists and Plants

2. Haplontic Life Cycle of Chlamydomonas
Resting spore withstands poor conditions
To observe: Place a drop from the cell culture between a slide and cover slip.
Photosynthetic protist showing an early eukaryotic life cycle
No mitosis in diploid phase

3. Haplontic Life Cycle of Ulothrix
Isogametes fuse to form diploid zygote
Gametangium: cell that produces gametes by mitosis
Photosynthetic Protist
No mitosis in diploid phase
Zygote produces spores by meiosis
Haploid gametophyte grows from spore by mitosis
Gametophyte can produce gametes or zoospores
Motile spores (zoospores) formed by mitosis or meiosis
Sporangium: cell that produces spores by mitosis
Spore: haploid cell that can grow by mitosis
Gametophyte: multicellular haploid structure that produces gametes
Haplontic Life Cycle of Ulothrix

4. Haplontic Life Cycle of Ulothrix
To observe: Place a drop from the cell culture between a slide and cover slip. Include some green fibers in your sample.
You do not need to distinguish between gametangia and sporangia.
Haplontic Life Cycle of Ulothrix

5. Diplohaplontic Life Cycle of Ulva
Photosynthetic Protist
Introduction of Mitosis in Diploid phase
Gametophyte produces isogametes
Isomorphic gametophyte and sporophyte
Sporophyte: multicellular diploid structure that produces spores by meiosis

6. Diplohaplontic Life Cycle of Ulva
To observe: Use a scalpel and/or forceps to take a small sample of the leafy structure and place it between a slide and cover slip.
You do not need to distinguish between sporophytes and gametophytes.
Diplohaplontic Life Cycle of Ulva

7. Diplontic Life Cycle of Fern
Archegonium: organ that produces eggs by mitosis
Plant
Smaller gametophyte
Larger, longer-lived sporophyte with tissues and organs
Spores produced by meiosis in sporangia on the underside of sporophyte leaves
Antheridium: organ that produces sperm by mitosis
contain sporangia (singular: sorus)

8. Prepared Slide: Mature Antheridia
Sperm within Antheridia
Gametophyte with Antheridia

9. Prepared Slide: Mature Archegonia
Each archegonium contains one egg
Gametophyte with Archegonia

10. Prepared Slide: Young Sporling
Gametophyte

11. Observation: Sorus, Sprorangia and Spores
To observe: Scrape some material from the underside of a fern leaf onto a slide. Distribute it into a thin layer. Add a cover slip. Adding water is optional.
Sporangium
Indusium