Plant Diversity
The Origin of Plants from Algae
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Plants evolved from algae.
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Oldest plant fossil is 475 millions years old!
Plant- multicellular autotroph in which the
embryo develops within the female parent.
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Multicellular?
Autotroph?
Embryo?
Challenges of Life on Land
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1) Obtaining resource
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Air
Soil
2) Staying upright
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Lignin- hardens cell walls
Challenges of Life on Land
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3) Maintaining moisture
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Cuticle- helps the plant to maintain moisture
Stomata- pores for gas exchange
4) Reproducing
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Plants must keep offspring
from drying out
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Seeds in “jacket”
Embryo develops in female
Plant Diversity
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Charophytes- algae
ancestors; lived in shallow
water
Bryophytes- no seeds
(mosses)
Pteridophytes- ligninhardened tissue (ferns)
Gymnosperms- “naked”
seeds (conifers)
Angiosperms- seeds in
ovaries (flowering plants)
Video
Angiosperms
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Reproductive structures are flowers
Embryo develops within the female (in the
flower)
Flower Structure
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FLOWER- reproductive
structure in angiosperms
Stamen- Male part
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Anther- at tip; produces
pollen (which contains sperm)
Filament- stalk
Carpel- Female part
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Ovary- Chamber that holds
the embryo in the carpel (the
“fruit”).
Fruit or Vegetable?
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Fruit- ovary protecting SEEDS
Vegetable- edible roots, stems, or leaves
Computer Activity
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Phsuccessnet.com
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19.1, 19.5
Turn in when completed in bin.
Start homework.
Transpiration Lab
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Transpiration- Loss of water from a plant,
especially from the leaves.
Transpiration Lab
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Photosynthesis: How a plant makes food;
occurs in the chloroplast.
Transpiration Lab
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Make a testable hypothesis to answer this
question:
“How is plant transpiration rate affected by
light?”
Transpiration Lab
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Data Table
Transpiration Lab
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Variables
Flower Dissection
Reproductive structures
male: stamen anther + filament
female: carpels
ovary + style + stigma
Flower Dissection
(carpel)
Flower Function
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Reproduction (“pollination”)
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Insect-pollinators
Wind-pollination
Pollination
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Endosperm- nutrientstoring tissue; feeds the
embryo as it develops
Fruit- ripened ovary of
a flower; protect & help
disperse seeds
Double fertilization
1)
One sperm fertilizes egg cell zygote
2)
Other sperm fertilizes outside of ovary
forms ENDOSPERM: nutrients for embryo
3) Embryo + endosperm  seed
Seed dispersal
Animal parts
Hidden in fruits that are eaten or decomposed
Water
Wind
www.phsuccessnet.com
Seed development
Root & shoot emerge
cotyledons helps plant get nutrients
dicot: two
http://www.hobart.k12.in.us
monocots: one
Seed development
http://images.encarta.msn.com/xrefmedia/aencmed/targets/illus/ilt/T630888A.gif
Germination
Absorbed water splits seed coat.
Shoot makes its way to surface.
Root grows down.