Parts of the Embryo:a. Plumule (epicotyl) part ofshoot that gives rise to thefirst true leavesb. Radicle = root systemc. Hypocotyl = becomes the stem of the new plant
Parts of the Embryo:a. Plumule (epicotyl) part of shoot that gives rise to the first trueleavesb. Radicle = root systemc.Hypocotyl = becomes the stem of the new plantd. Cotyledon(s) = seed leaves of the embryo; provides nutrients for embryo
A seed can have:•one cotyledon called monocots ex. corn or•two cotyledons called dicotsex. lima beans
Parts of a seed: 1. Embryo – plant itself 2. Seed coat – protective covering some seeds have a double coat some seeds have a hilum or scar where they attached to the ovary
Parts of a seed: 1.Embryo 2. Seed coat 3. Endosperm = additional stored food found in monocots that surrounds the embryo.
•Germination - sprouting of theseed•Dormancy - period of inactivityto help seed not sprout duringbad conditions
•Viabilityability of seeds to germinate or (howlong a seed can wait and still sprouts)some seeds are viable only a few daysothers for thousands of years – there isgreat variation in viability Indian lotus viable thousands of years
Steps to germination: 1. plant absorbs water 2. seed coat softens 3. root and shoot push through soil 4. energy used from cotyledons andendosperm through process of cellularrespiration (starch – sugar-energy) 5. Growth of stem, leaves and root.Cotyledons often grow with stemprotecting leaves and providing energy.
Factors affectinggermination:1. Moisture – biggie, seed goes from 10% water to 200% water2. Oxygen for cellularrespiration3. Temperature – best 68-86F4. Soil – varies in quality
George WashingtonCarverCalled “the Plant Do ctor”Taught agriculture atTuskegee InstituteStudies chemurgi or waysto use plants to makeproducts