plant reproduction notes
TRANSCRIPT
Plant Reproduction
LOTS OF KINDS OF PLANTS...
Angiosperms (flowering plants)• Plants that protect their seeds within the body
of a fruit.• Make up ¾’s of all plants, including:–Trees, shrubs, herbs, grasses, water plants…
Which plants make fruit?
• Orange tree? • Avocado tree?• Pumpkin plant?• Zucchini plant?• Tomato plant?• Wheat plant?• THEY ALL MAKE FRUIT (Fruit is the edible part
that surrounds seeds).
The Stamen:Male Reproductive Structure
Consists of two parts: Anther and Filament
The filament is a stalk that supports the anther
The anther is where meiosis occurs to produce pollen
Each pollen grain contains sperm cells.
The Pistil:Female Reproductive Structure
Consists of the stigma, style and ovary
The sticky stigma receives the pollen from the anther
The pollen grows a tube down through the style
Each ovule contains an egg cell.
Male Parts Female Parts Stamen consists of: 1. Anther 2. Filament
Pistil consists of: 1. Stigma 2. Style 3. Ovary (ovules inside)
Reproductive Structures
• Petals: colorful structures that attract
pollinators.
• Sepals: surround and protect the flower bud.
Sepals: protect immature buds
Pollination
Wind, insects or other animals transfer pollen from the anther of one flower to the stigma of another
Flowers vary depending on pollination mechanism
PollinationWind Pollination: Dull, scentless flowers with reduced petalsBees/Butterfly Pollination: Brightcolor, nectaries, scent. They sip nectar, get pollen on coats, transfer pollen from flower to flower
Bird Pollination: Nectaries, brightcolors, tube-like flowersMoth Pollination: White petals, open at night
Fly Pollination:Rank odor, fleshcolored petals
Tip of a tulip stamen with many grains of pollen.
Scanning electron microscope image of pollen grains from a variety of common plants: sunflower, morning glory, prairie hollyhock, oriental lily, evening primrose, and castor bean.
• Pollen Grain • Anther Sac
Pollen grains contain two haploid cells produced through meiosis.
1- The Tube cell – will grow the pollen tube. 2- The Generative cell – will go through meiosis to create two sperm cells.
tube cell
generative cell
Seed and Fruit Development After fertilization,
the petals and sepals fall off flower
Ovary “ripens” into a fruit
The ovule develops into a seed
See Fig 13 on page 139 Life Science Text
Seed Dispersal Mechanisms-Allow plants to colonize new areas and avoid
shade of parent plant
Wind Dispersal - Flight mechanisms, like parachutes, wings, etc. Ex. Dandelion, maples, birch
Animal Dispersal - Fleshy fruits which animals eat, drop undigested seeds in feces or burrs which stick to animals’ coats
Gravity Dispersal - Heavy nuts fall to ground and rollex. acorns
Water Dispersal - Plantsnear water create floating fruitsex. coconuts