Objective 3.02

Objective 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

Leaves-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 plantPhotosynthesis vs. Respiration

Sessile describes leaves without a petioleExample zinniaBracts are modified leavesExample poinsettiaNeedles and scales are modified leavesExample pine treeLeaves-Additional TermsLeaves-Additional Terms

Leaves-AdditionsGlabrous leaves or stems have a smooth non-hairy feelExample southern magnoliaPubescent leaves or stems have a hairy feelExample African violet

Stems-ExternalLenticels-breathing pores found on stems and branchesBud scale scars-show where terminal buds have been locatedLeaf Scars-show where leaves were attachedTerminal bud-bud on the end of a stemAxillary bud- bud located at the leaf axilLateral bud- bud on side of stem

Stems-External

Stems-External

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-Internal

Stems-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-Internal

Stems-InternalCambiumHeartwoodSapwoodBarkStems-InternalMonocots-plant stems have vascular bundles that contain both xylem and phloem in each bundle. Produce one seed leaf.examples: corn, grassesDicots-plant stems have the phloem layer and xylem layer separated by cambium. Produce two seed leavesexample: trees, many vegetable plants

Stems-InternalMonocotDicotStems-Internal

Stems-FunctionsTranslocation- the movement of water and minerals through the plantPhloem moves food down from leaves to rootsXylem moves water and nutrients up from roots to leavesStems provide support for the branches of the plantRoots-ExternalRoot cap- located at the tip of the root and is where new cells are producedRoot 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 stemTypes of RootsFibrous-many branched shallow rootsare easier to transplantTap-long root with few branched onesmore difficult to transplant

Functions of RootsAnchorageAbsorptionAsexual reproduction (propagation)StorageFlowersSepals-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

StigmaStyleOvaryFunctions of FlowersAttracts insects for pollinationProduces seeds for sexual reproductionProduces fruit to nourish and protect the seed

Additional Flower and Fruit TermsComplete flower- has both male and female partsIncomplete flower- has only male or female partsAdditional Flower and Fruit TermsFertilization when pollen travels down the style, joining the sperm and the ovulePollination transfer of pollen from the anther to the stigmaCross-pollination transfer of pollen from the stamen to the stigma of one flower to a flower on another plantSelf-pollination transfer of the pollen to the stigma of a flower on the same plantAdditional Flower and Fruit TermsCorolla all auxiliary parts of the flower not including reproductive organsCollective term for all petals of a flowerCalyx external, usually green or leafy part of a flowerCollective term for all sepals of a flowerReceptacle enlarged tip of stem on which a flower is borneFruit serves as protection for seedsFunction of fruit is to help with seed dispersalREVIEW OF FUNCTIONS!What 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 seeds