Plant Parts and their Functions

Plant Parts and their Functions1Leaves-Internal

2Upper Epidermis: single layer of cells used to protect the leaf from loss of too much moisture.Guard Cells: open and close the stoma to allow the leaf to breathe and transpire (will open when the plant becomes turgid)Stoma: space or pore on the underside of the leaf that is used to exchange gases as oxygen and carbon dioxide (transpiration)Chloroplasts: green particles that contain chlorophyll and are contained in food making cellsChlorophyll: the green substance that gives many plants their green color and is necessary for photosynthesisPhotosynthesis: process by which carbon dioxide and water in the presence of light are converted to sugar and oxygen. (begins the food chain process for all living things) 6CO2 + 6H20 + 672kcal(kilocalorie) = 6C6H12O6 + 6O2 or carbon dioxide + water + light energy = glucose (sugar) + oxygenFood is moved through the leaves down to the roots to be stored in the form of sugar, starch or protein.Molecular ExpressionsLeaves-InternalChloroplasts-small green particles that contain chlorophyllgives leaves their green colornecessary for photosynthesis

5Leaves-InternalAir Space: CO2 & O2

Vein: Movement of Fluid

Xylem: transport water up

Phloem: transport glucose

4Leaves-Internal

6Functions of LeavesPhotosynthesis-manufactures food in green plants which is the beginning of the food chain for all living thingsPhotosynthesis is the process by which carbon dioxide and water in the presence of light are converted to sugar and oxygen7Functions of LeavesTranspiration loss of water through the leaves or stems of plantsTranspiration exchange gases as oxygen and carbon dioxide 8StemsMovement of Materials

Support of the leaves and reproductive structures

Food storages

Reproduction with stem cuttings or grafting9Stems-Internal (dicot)

10Stems-InternalPith-dead center of stem for supportHeartwood-old inactive xylemSapwood-new active xylemCambium-thin, green, actively growing tissue located between bark and wood and produces all new stem cellsPhloem-activeBark-old inactive phloem

11Stems-Internal (Translocation)Xylem-tissue that transports water and nutrients up from the roots to stems and leavesPhloem-tissue that transports food down from leaves to rootsPhloemPhloemXylem12Stems-InternalMonocot : examples: corn, grasses

Dicot: example: trees

13Cotyledons -The primary leaf of the embryo of a seed plant that either remains in the seed or emerges upon seed germination14Functions of StemsTranslocation move water and minerals from roots up to leaves & move food from leaves down to the rootsXylem and phloem cells help with this process.15Functions of Stems & LeavesTranspiration plant lose water from leaves and stems through evaporationOccurs in stomas and lenticels16Root FunctionsAnchor the plant and hold it uprightAbsorb water and minerals from the soil and conduct them to the stemStore large quantities of plant foodPropagate or reproduce some plants17Roots-InternalMuch like stems in that they have a phloem, cambium, and xylem layerPhloem-the outer layer that carries food down the rootXylem-the inner layer that carries water and minerals up to the stem18Layers of RootsFibrous-many branched shallow rootsare easier to transplantTap-long root with few branched onesmore difficult to transplant19Functions of RootsAbsorption-take water and nutrients from the soil and conduct them to the stemAnchor the plant and hold it uprightStore food for plant useAsexual reproduction in some plants20DioeciousMale and female, imperfect flowers on same plantExamples: Squash & Pumpkin

21Functions of FlowersProduce seeds used for sexual reproductionAttract insects for pollination (Pollination is the transfer of pollen from anther to stigma.)Produce fruit to protect, nourish and carry seeds22Functions of Whole PlantRespiration the process through which plant leaves, stems and roots consume oxygen and give of carbon dioxide.Plants produce much more oxygen through photosynthesis than they use through respiration.23