Plant-People Interactions

Plant-People Interactions - Plant-People Interactions 1 st...

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Unformatted text preview: Plant-People Interactions 1 st Day Botany = study of plants Importance of plants:- Food- Medicine - Shelter- Clothes- Clean air- Currency- Energy- Aesthetic beauty- Oxygen Basic plant structure Roots- Below ground- First structure to emerge from the seed- Main functions: + Absorption of water and minerals + anchor plant Modified roots Grasses have many roots- Good for holding soil and preventing erosion Tropical trees have buttresses- Root start above ground and help anchor tree Food storage- Root stores food from first year- Some biennial crop plants: carrot, sweet potato Stems- Above ground- Main functions: + support leaves for maximum photosynthesis +support flowers to attract pollinators + conduct food and water Modified stems Water storage- Many succulents have swollen stems (green part of cactus) Support- Vines have tendrils: grapevine, watermelon Food storage- Some plants have bulbs or tubers: tulips, potatoes Leaves- Usually green, borne on stems- Main functions: + photosynthesis + transpiration Modified leaves Pollinator attractants- Colorful leaves surround small flowers: poinsettia, bougainvillea Protection- Spines are hard and sharp Support- Vines have tendrils: peas, beans Reproductive structures Flowers- Only produced by some plants- Attract pollinators- color, nectar, odor- Often have male and female parts in the same flower Fruits- Every flowering plant produces fruit- Protects seeds, aids in dispersal by wind, water, animals Seeds- Embryo- Food source- Seed coat Seeds Good food source for humans- Stored food for embryo- Produced in large quantities- Easily harvested without harm to parent plant Types of plants Non-vascular plants (mosses)- Simplest, small, no true vascular system Seedless vascular plants (ferns) Gymnosperms (conifers)- Can be very large, produces seeds but no flowers Angiosperms (flowering plants)- Produce flowers and fruit, vast diversity We will concentrate on angiosperms- Most familiar to humans- Most economically important- 2 nd Day Agriculture = cultivation of plants Domestication = genetic alteration of plants by humans Knowledge of foraging societies Archaeological evidence- Middens - Coprolites Modern evidence- !Kung- Ainu Why did we start farming? Previous explanation: theory of the brilliant sage- Sow seeds= grow crops- Plants growing in middens from discarded seeds- Seeds buried with dead sprouted Did agriculture start in 1 region? Fertile Crescent, ,Cradle of Agriculture China, Papua New Guinea, Americas Possible reasons Climate change- Mid. East got drier around 11,000 years ago- People crowded around water supplies Population increase- May have gotten too big to support hunter-gatherer lifestyle Selection Selection- Occurs constantly in population of plants- Certain traits/characteristics/alleles always being selected for/against Natural selection- Occurs in wild population containing natural variation...
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This note was uploaded on 02/06/2012 for the course NAT_SCI 210 taught by Professor Somebody during the Winter '11 term at Northwestern.

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Plant-People Interactions - Plant-People Interactions 1 st...

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