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Plants Continued. Plant Sex. Pollen Grain – male gamete – many forms of distribution – wind, animal, water Ovule – Female gamete – inside flower. Pollination – transfer of pollen from anther to pistil Pollen makes a pollen tube to egg then fertilizes the egg, makes seeds. Ovules. Ovules.
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Plant Sex • Pollen Grain – male gamete – many forms of distribution – wind, animal, water • Ovule – Female gamete – inside flower
Pollination – transfer of pollen from anther to pistil • Pollen makes a pollen tube to egg then fertilizes the egg, makes seeds
Pinecones – reproductive organs • Modified leaves formed in circles • Male cones contain pollen • Female cones open for pollination then close until seeds mature then reopen for dispersal – can take up to 2 years
Asexual Reproduction in plants • Vegetative – modified stems (runners, bulbs, tubers, rhizomes)
Plant Parts • Vascular tissues – vessels that carry nutrients & water through the plant • - xylem – carries water and minerals up from roots • - phloem – carries sugars down & around • Roots – take up water & nutrients from soil, anchor plant
Stem – houses vascular tissues & supports leaves – 2 types • 1. woody – non-green • 2. herbaceous – green, flexible
Leaves- major photosynthetic organ of plant • - blade – flat part • - petiole – stem • If blade is divided, called leaflets
Germination • Embryo resumes growth, root emerge 1st, shoot 2nd • Some plant first send a hook up to protect plant others send up cotyledons
Plant Life Span • Perennial – all woody, some herbaceous - live several years - most reproduce several times – some only once • Annual – grows, flowers, reproduces & dies in 1 growing season – almost all herbaceous - corn, beans, sunflowers
Biennial – live 2 seasons – carrots, onions – 1st year stores nutrients – 2nd year produces flower, makes seeds and dies
Plant Behaviors • Tropisms – response when a plant grows toward or away from a stimulus • - toward=positive tropism • - away=negative tropism
Dormancy – some plants or seeds remain inactive until they have been exposed to low temps for several weeks