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.