Chapters 23-26. All Plants… multicellular, eukaryotic, autotrophic.
PLANTS eukaryotic autotrophic (through photosynthesis) cells have walls made of cellulose.
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Transcript of PLANTS eukaryotic autotrophic (through photosynthesis) cells have walls made of cellulose.
PLANTS• eukaryotic• autotrophic (through
photosynthesis)• cells have walls made
of cellulose
ALTERNATION of GENERATIONS
• Animals are diploid individuals with only haploid stages in sperm and egg.
• Plants alternate between a haploid and a diploid generation.
• Diploid (2n) = sporophyte; haploid (n) = gametophyte.
HIGHLIGHTS OF PLANT EVOLUTION
Four key adaptations to life on land
1. Dependent embryos, which are nourished and protected on the parent plant.
2. Vascular tissues (xylem and phloem) transport water, nutrients and provides support for upright stems found in most modern plants..
3. Seed producers appeared and these plants dominate the plant kingdom today.
4. Flowers provide a new process for plant reproduction.
Evolution of Plants
Transport
Phylum Examples
Non-vascular(live in water)
Algae Seaweed (unicellular, colonial, & multicellular)
Bryophytes Moss, liverworts
Vascular(true land plants)
Pteridophytes Ferns, horsetails
Gymnosperms
Evergreen trees
Angiosperms Flowering plants
Unicellular AlgaeEuglena & Diatoms
– protists or plants?
Chlamydomonas (right) - unicellular.- moves using flagella.
Volvox – lives in colonies. Some cells are specialized!
Unicellular to Multicellular Plants
• Unicellular-all of life’s activities occurs within a single cell.
• Colonial – Some cell specialization distributes jobs.
• Multicellular-various specialized cells, which perform different functions and are interdependent.
Spirogyra – multi-cellular- cells are stacked end to end.- specialization of some cells.
Ulva (sea lettuce)– multi-cellular- releases gametes for reproduction.
Green Algae
Brown Algae
Red Algae
Chlorophyll A & B
Chlorophyll A & C
Chlorophyll A & D
Algal Structur
e
Blade - thin for diffusion of nutrients & gas- photosynthetic- may secrete mucous
Float (air bladder) – brings algae closer to surface and sunlight
Stipe- photosynthetic extension
Holdfast- anchors algae
Kelp Forests
Provide habitat for numerous organisms
and minimize the pounding
effects of waves.
- Drying out
- transport of nutrients.
- Reproduction(sperm moving to egg)
Challenges of
moving to land!
Bryophytes (moss, liverworts, & hornworts)
BryophytesCan survive on land but are heavily
dependant onwater.This is why they like shady areas.
• Depend on diffusion for transport• Are thin and dry out easily• Sperm need to swim to the egg• Have rhizoids instead of true roots
Moss have a dominant haploid gametophyte generation
Life cycle of a moss
Pteridophytes (ferns)
Pteridophytes
• Have true roots and vascular tissue for transport up stem.
• Have a waxy cuticle on fronds (leaves) to prevent drying out.
• Sperm do still need water to swim to the egg on the prothallus
Ferns have a dominant diploid sporophyte generation
Life cycle of a fern
Gymnosperms(evergreens)
• Have cones for reproductive structures.• Rely on wind for pollen dispersal from
the smaller male cone to the larger female cone.
• Produce exposed (“naked”) seeds on their cones.
• Have tough needles which withstand cold climates.
Gymnosperm Lifecycle
Singlefertilization
Angiosperms(flowering plants)
• Have flowers for reproductive structures.
• Use wind and animals for pollen dispersal
• Produce protected seeds that contain food for their embryo.
• Have broad flat leaves.
Plant Porn???
Plant Peep Show
Angiosperm Lifecycle
Doublefertilization
Flower Diversity