Transcript Life Cycles Laboratory

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
Gametangium:
cell that
produces
gametes by
mitosis
Isogametes fuse
to form diploid
zygote
•
•
•
•
Sporangium:
cell that
produces
spores by
mitosis
•
Spore:
haploid
cell that
can grow
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
Gametophyte:
multicellular
haploid structure
that produces
gametes
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.
Haplontic Life Cycle
of Ulothrix
You do not need to
distinguish between
gametangia and
sporangia.
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
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
• 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)
Archegonium:
organ that
produces eggs
by mitosis
Prepared Slide: Mature Antheridia
Sperm within
Antheridia
Gametophyte with Antheridia
Prepared Slide: Mature Archegonia
Gametophyte with Archegonia
Each archegonium
contains one egg
Prepared Slide: Young Sporling
Sporling
Gametophyte
Observation: Sorus, Sprorangia and Spores
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.
Indusium
Sporangium