Plants Continued

Plants Continued

Plant SexPollen 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

Pinecones – reproductive organsModified leaves formed in circles

Male cones contain pollenFemale cones open for pollination then close until seeds mature then reopen for dispersal – can take up to 2 years

Asexual Reproduction in plantsVegetative – modified stems (runners, bulbs, tubers, rhizomes)

Plant PartsVascular 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-green2. herbaceous – green, flexible

Leaves- major photosynthetic organ of plant

- blade – flat part- petiole – stemIf blade is divided, called leaflets

GerminationEmbryo resumes growth, root emerge 1st, shoot 2nd

Some plant first send a hook up to protect plant others send up cotyledons

Plant Life SpanPerennial – 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 BehaviorsTropisms – 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