Plantstart! 11/5
• Why do plants make flowers?Write your answer based on what you already know.
Yes – I know I still have your Journals – take out a piece of paper!
LOTS OF KINDS OF PLANTS...
Plant Reproduction
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?
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)
Antherstart! 11/6
• Name the two parts of the male reproductive structure of the plant.
• Name the three parts of the female reproductive structure.
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
Pollination VectorsWind 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 flowers
Moth 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