PLANTS

Plants: Grouped by characteristics Nonvascular –Simple; most grow in moist places –No vascular tissues. No way to move around water and nutrients Need to live close to water Mosses, liverworts, ferns Evolved first Vascular –Have Vascular tissues: roots, stems and leaves –Allows them to grow large and in many different environments –Includes trees, flowering plants, crops, etc….

Non vascular = Bryophytes Only nonvascular plants (mosses, liverworts) no ability to internally transport water and materials requires moist environment live in colonies, has rhizoids to anchor it important in soil formation

Vascular Plants - Tissues Plants have 3 tissue systems: Ground tissue –Photosynthesis, food storage, regeneration, support, protection Vascular tissue (xylem and phloem) –Movement of materials Dermal tissue (exterior) –Protection and prevention of water loss

Plants: Stems Function of stems –Support, transport of water & food Green Woody –Transport of materials xylem - conducts water and minerals phloem - conducts food

Growth Plant growth occurs at specialized areas called meristems (meristematic tissue) Primary growth = growth in length Secondary growth = growth in girth

Leaf function Photosynthesis - more later Transpiration - 99% of water absorbed by plant is lost by transpiration Stomata are tiny holes on the bottom of the leaf that let gases and water in and out –Opening controlled by guard cells

Photosynthesis chlorophyll – the green substance found in plants that traps energy from the sun and gives plants their green color chloroplasts - where photoysynthesis happens  Uses carbon dioxide, water, and sunlight - reactants  Releases oxygen and makes sugar, oxygen is released - product

Plant Evolution First = Bryophytes - no roots, leaves or stems, no vascular system, simple reproduction relying on water. Second = Ferns - first vascular system –Reproduce using spores

Gymnosperms Vascular, seed bearing, flowerless plants means “naked seed” largest division is conifers leaves are called needles Pines, cedars, spruces, firs

Angiosperms Flowering, vascular plants Most successful plants: deciduous trees Magnolias, roses, apple trees Plant Parts –Pistil – part of a flower that makes the eggs that grow into seeds –Stamen – part of a flower that makes pollen –Pollen – tiny grains that make seeds when combined with a flower’s egg monocot seed – a seed that has one seed leaf and stored food outside the seed leaf dicot seed – a seed that has two seed leaves that contain stored food

Plant Adaptations Specialized tissues – vascular tissues Cuticles –Waxy coating on surfaces –resists drying out –stomata exist to allow necessary gas exchange Alternation of generations –Plants live part of their life in a haploid stage and part in a diploid stage –haploid portion = gametophyte –diploid portion = sporophyte Co-evolution with pollinators