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Group Four Seeded, vascular plants (ex: a ngiosperm). stamen. filament. anther. stigma. style. carpel. ovary. sepal. petal. Quick REVIEW: Flowers C ontain R eproductive O rgans P rotected By Specialized L eaves. Sepals and petals are modified leaves.
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stamen filament anther stigma style carpel ovary sepal petal Quick REVIEW: Flowers Contain Reproductive Organs Protected By Specialized Leaves • Sepals and petals are modified leaves. • Sepals are outermost layer that protectsdeveloping flower • Petals can help to attract animal pollinators • A stamen is the male structure of the flower • Anther produces pollen grains • Filament supports the anther • The innermost layer of a flower is the female carpel. • Stigma is sticky tip • Style is tube leading from stigma to ovary • Ovary produces female gametophyte
Flowering plants can be pollinated by wind or animals • Wind pollinated flowers have small flowers and large amounts of pollen. • Animal pollinated flowers have larger flowers and less pollen. Many flowering plants are pollinated by animal pollinators. • Pollination occurs as animal feeds from flower to flower • Animal pollination more efficient than wind pollination
Fertilization Takes Place Within The Flower Cell that will divide & become the pollen tube • Male gametophytes (pollen grains) are produced in the anthers. • Male spores produced inanthers by meiosis • Each spore divides bymitosis to form twohaploid cells • Two cells form asingle pollen grain Cell that will divide & become 2 sperm Pollen grain Stamen Anther Filament
One Female Gametophyte Can Form In Each Ovule of AFlower’s ovary • Many cells can be made in the ovule • One cell becomes the egg • One cell becomes 2 polar nuclei • The rest die Ovule (Egg) [ 2 Polar Nuclei (Each = 1n)
Angiosperm Life Cycle 1. Pollen sticks to animal or is released into wind.
2. Animal finds new flower to feed on & pollen grains land on the stigma (pollination) 3. Pollen tube grows towards the egg and 2 nuclei transfer down into the ovule .. Let’s zoom in egg
4. Angiospermsgo through the process of double fertilization. • 1 sperm fuse with the egg = zygote • 1 sperm fuse with the polar nuclei = triploid (3n) endosperm Double Fertilization Endosperm (3n) Zygote
Endosperm Seed Coat Embryo • Endosperm provides food supply for embryo 5. Each ovule becomes a seed. 6. The surrounding ovary grows into a fruit.
9. Seeds get dispersed. 10. Seed germinates (sporophyte), and the cycle starts over. Ground