Plant Parts and their Functions

Plant PhysiologyEssential Standard 3.00: Summarize Plant AnatomyObjective 3.01Discuss biological terms used to describe plants.Plant SciencesBiology-the branch of science that deals with both plant and animal organisms and life processesZoology-the part of biology that deals with animalsBotany the part of biology that deals with plantsPlant SciencesApplied plant sciences are based on the purposes for which the plants are grownAgronomyForestryHorticulture

AgronomyThe science and practice of growing field crops such as cotton, wheat, tobacco, corn and soybeans.

ForestryThe science and practice of growing, managing and harvesting trees for building materials and other products.

HorticultureThe science and practice of growing, processing and marketing fruits, vegetables, and ornamental plants

Life Cycles of PlantsAnnual-a plant that completes its life cycle in one yearBiennial-a plant that completes its life cycle in two yearsPerennial-a plant that lives more than two yearsLeaf RetentionDeciduous-loses leaves during the dormant seasonEvergreen-keeps leaves and remains green year-round

Plant HormonesSeveral types of hormones are used to help plants work more efficiently.InhibitorscytokininsgibberelliasauxinsInhibitorsInhibitors hasten fruit ripening, retain seed germination and stem elongation.

CytokininsHormones that work with auxins to stimulate cell division.GibberelliasHormones that stimulate cell elongation, premature flowering, and breaking of dormancy.

AuxinsHormones that speed plant growth by stimulating cell enlargement

Moisture in PlantsTurgid-plant is swollen or filled with moistureWilted-plant is limp because it does not have enough moisture

Plant GrowthDormantA plant rest or grows very littleResponse to an adverse condition

Season Crop TypeCool SeasonPlants relish cool weatherPansies grow best in spring or fallWarm SeasonGrow best in summer and early fallZinniaMarigoldVincaPoinsettiaObjective 3.02Discuss the anatomy and functions of plants.

Leaves-ExternalPetiole-Leaf stalk or part that connects the leaf to the stemBlade-The large, flat part of the leafMidrib-The large center veinVeins-The structural framework of the leafMargin-The edge of the leafApex Leaf Tip Leaves-External

Leaves-InternalUpper and lower epidermis-skin of the leaf that prevents the loss of too much moistureStomates-small openings under the leaf for breathing or transpirationGuard Cells-open and close stomatesLeaves-InternalChloroplasts-small green particles that contain chlorophyllgives leaves their green colornecessary for photosynthesis

Leaves-Internal

Leaves-Internal

Leave-FunctionsPhotosynthesisprocess by which plants capture sunlight and use it to convert carbon dioxide and water into foodRespirationconverts sugars and starches into energyTranspirationrelease of water vapor from the leaves of plantsIt also cools the plantSessile describes leaves without a petioleExample zinniaBracts are modified leavesExample poinsettiaNeedles and scales are modified leavesExample pine treeLeave-AdditionsLeave-AdditionsGlabrous leaves or stems have a smooth non-hairy feelExample southern magnoliaPubescent leaves or stems have a hairy feelExample African violet

Stems-ExternalLenticels-breathing poresBud scale scars-show where terminal buds have been locatedLeaf Scars-show where leaves were attachedTerminal bud-bud on the end of a stemAxillary or lateral bud-bud on side of stem

Stems-InternalXylem-tissue that transports water and nutrients up from the roots to stems and leavesPhloem-tissue that transports food down from leaves to rootsStems-InternalPhloemPhloemXylemStems-InternalCambium-thin, green, actively growing tissue located between bark and wood and produces all new stem cellsBark-old inactive phloemHeartwood-old inactive xylemSapwood-new active xylemStems-InternalCambiumHeartwoodSapwoodBarkStems-InternalMonocota-plant stems have vascular bundles that contain both xylem and phloem in each bundleexamples: corn, grassesDicata-plant stems have the phloem layer and xylem layer separated by cambiumexample: trees

Stems-InternalMonocotDicotRoots-ExternalRoot cap-indicates growth of new cellsRoot hairs-absorb moisture (water) and minerals

Root images from a rice plantRoots-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 stemLayers of RootsFibrous-many branched shallow rootsare easier to transplantTap-long root with few branched onesmore difficult to transplant

FlowersSepals-Green parts that cover and protect flower bud before it opensPetals-are really leaves that are modified to attract insects for flower pollination, the pretty part that we call flowersStamen-male part of the flowerPistil-female part of the flowerFlowers

Parts of the StamenFilament-short stalk that holds up the antherAnther-a sac-like structure that contains pollen, the male sex cells

Parts of the PistilOvules-the eggs or female sex cells that become seeds if fertilizedOvary-if fertilized becomes a fruit or seed coatStyle-holds up the stigma and connects it to the ovaryStigma-sticky part on top of style where insects leave pollenParts of the Pistil

StigmaStyleOvaryComplete-vs-IncompleteComplete flowers have both male and female partsIncomplete flowers have only male or female partsWhat are the functions of these plant parts?Functions 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 oxygenFunctions of StemsTranslocation-moves water and minerals from roots up to the leaves and move food from the leaves down to the rootsSupports branches, leaves, flowers, fruits and seedsFunctions 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 plantsFunctions 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 seedsObjective 3.03Discuss floriculture and landscape plantsTaxonomyThe science of classifying and identifying plantsScientific names are used because the same common name is used for different plants in different areas of the world.

Karl von LinneSwedish botanist that developed the binomial system of naming plants using two Latin words to indicate the genus and species.Linne changed his name to the Latin name Carolus Linneaus.

Scientific NamesLatin is the language used for scientific classification.The first word is the genus and the second word is the species. If there are additional words, they indicate a variety or cultivar.Genus vs. SpeciesPlants in the same genus have similar characteristics.Plants in the same species consistently produce plants of the same type.Scientific ClassificationThe broadest category of scientific classification is the Kingdom--either plant or animal.The broadest category in the plant kingdom is division or phylum.DivisionsThe four most important divisions of the plant kingdom are:ThallophitesBryophytesPteriophytesSpermatophytesSpermatophytesContains flowering or seed-bearing plantsTwo subdivisions are:Gymnosperms and AngiospermsCommon Plant GenusPinus-Pine

Acer-Maple

Ilex-Holly

Ficus-figCornus-dogwood

Rhododendron-rhododendron

Quercus-oak