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Plant Life CyclesPlant Life Cycles

Chapter #2

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What is a Life Cycle?What is a Life Cycle?• from the time a seed is planted until

a seed is produced

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What are the Life Cycles?What are the Life Cycles?• Annuals, Biennials, & Perennials

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AnnualAnnual

• complete life cycle in one growing season

• can be summer annuals (spring wheat, barley) or winter annuals (winter wheat)

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BiennialsBiennials

• require two growing seasons to produce seed

• first season plant produces vegetation, second season seed (sugar beet, carrot)

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PerennialsPerennials

indefinite growth, can produce seed annually (grasses, trees, shrubs, onion)

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What is a Seed?What is a Seed?• package containing an embryo

(miniature plant) and food• seeds are alive, need air

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What is Germination?What is Germination?• process where embryo changes to

seedling (growing plant)

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What conditions are What conditions are necessary for necessary for germination?germination?

1) moisture2) correct temperature3) air4) some seeds need light5) some seeds need help (break seed

coat [sunflower], remove a chemical from seed, heat, chill [winter wheat])

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What are Warm Season What are Warm Season Crops?Crops?

• soil temperature must be 70 degrees F or more for germination (corn, rice, cotton, melons)

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What are Cool Season What are Cool Season Crops?Crops?

• soil temp below 70 degrees F (wheat, barley, beets)

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How deep do seeds need How deep do seeds need to be planted?to be planted?

• the size of the seed determines• larger seed = deeper• corn = 4" • bluegrass = 1/4"

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Germination ProcessGermination Process1) seed absorbs water, swells2) water activates enzymes which help

digest stored food3) root grows4) shoot emerges (is now a seedling)

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What is vegetative What is vegetative growth?growth?

• plant produces food for itself• extra food is stored in roots, stems,

etc.

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What is Tillering What is Tillering (Stooling)?(Stooling)?

• when new stems are formed in grass plants

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What is Jointing?What is Jointing?• stems of grass plants elongate rapidly

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What is Respiration?What is Respiration?• process how plants get energy from its

stored food

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How is food stored in How is food stored in plants?plants?

• form of carbohydrates (sugars)

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How does respiration How does respiration work?work?

Food + Oxygen --> Carbon Dioxide + Water + Energy

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What factors can influence What factors can influence the rate of respiration?the rate of respiration?

1) high temps = high rate of respiration

2) high amounts of light = high rate

3) high amounts of water = high rate

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What is Photosynthesis?What is Photosynthesis?• process of converting water and carbon

dioxide into food (sugar) and oxygen in the presence of chlorophyll and light

• photosynthesis and respiration are opposite cycles

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What is Transpiration?What is Transpiration?• process of returning water to the air (in

the form of gas)• 99% of water taken in by roots is

transpired• Wilt = plant transpires more than it

takes in

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What are Nutrients?What are Nutrients?• elements needed by plants to grow

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What are Macronutrients?What are Macronutrients?• needed in large amounts• C, H, O, N, P, K, Ca, Mg, S)• plants get C, H, O from air and water

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What are Primary What are Primary Nutrients?Nutrients?

• N, P, K

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What are Secondary What are Secondary Nutrients?Nutrients?

• Ca, Mg, S• needed less

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What are Micronutrients?What are Micronutrients?• needed in small amounts, but essential• excess amounts are toxic• Fe, Bo, Mn, Zn, Mo, Cu, Cl

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16 Essential Nutrients16 Essential Nutrients• C HOPKNS CaFe Mg B Mn CuZn ClMo• C Hopkins Café Managed By Mine

Cousin Clomo

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