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