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

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

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

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

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

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

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)

Prepared Slide: Mature Antheridia Sperm within Antheridia Gametophyte with Antheridia

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

Prepared Slide: Young Sporling Gametophyte

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