2 A. Functions of Roots Anchor & support plant in the ground Slide 2A. Functions of RootsAnchor & support plant in the groundAbsorb water & mineralsHold soil in placeFibrous RootsRoot Hairs
3 B. Root TypesSlide 3Tap Root1. Fibrous Roots: branching roots hold soil in place to prevent soil erosionEx. Grasses2. Tap Roots –larger central root reaches deep water sources undergroundEx. Trees, Carrots, & Dandelions
4 C. The Structure of a Root Slide 4Root HairsRoot Hairs: increase surface area for water & mineral absorptionMeristem: region where new cells are producedRoot Cap: protects tip of growing rootPhloemXylemMeristemRoot Cap
5 A. Functions of Stems Support system for plant body Slide 5Support system for plant bodyTransport system carries water & nutrientsHolds leaves & branches uprightLooking at the picture to the left:What years had the most rain?What years experienced the worst drought?Each light and dark tree ring equals one year of annual growth. Light rings for fast spring growth, dark for slow summer growth.Smaller rings tell of past droughts that have occurred.
6 A. Functions of Leaves Main photosynthetic organ Slide # 6Main photosynthetic organBroad, flat surface increases surface area for light absorptionHave systems to prevent water lossStomata open in day but close at night or when hot to conserve waterwaxy cuticle on surfaceSystem of gas exchangeAllow CO2 in and O2 out of leafElephant Ear Plant
7 B. Leaf Structures Leaf Cross-Section Slide # 7Leaf Cross-SectionCuticle: waxy layer; covers upper surfaceProtects leaf against water lossVeins: transports water, nutrients and foodMade of xylem and phloemMesophyll: contains cells that perform photosynthesisb/c they contain Chloroplasts.CuticleVeinsMesophyllStoma(Opening)2 Guard CellsSurroundeachStomaStoma- singularStomata-plural
8 cells that open and close the stoma More Plant Parts…Slide # 8Guard cells:cells that open and close the stomaStomata: openings in leaf’s surface; when open:GAS EXCHANGE: Allows CO2 in & O2 out of leafTRANSPIRATION: Allows excess H2O out of leafGuard CellsStoma
9 Function of StomataSlide # 9What process involves using CO2 and H2O releasing O2 as a waste product?PhotosynthesisWhat is the plant using this process to make?Carbohydrates-glucoseIf the plant needs water for photosynthesis, why is water coming out of the stoma?Guard CellsGuard CellsWhat goes out?O2H2OCO2What goes in?Stoma OpenStoma ClosedStoma
10 Function of Guard Cells Slide # 10These stomata (leaf openings) naturally allow water to evaporate out.Why would the plant close stomata with guard cells?Prevent excess water loss through transpiration. (conserve water)So what is the point of having stomata?Allow gas exchange for photosynthesisGuard CellsGuard CellsStoma OpenStoma ClosedGuard cells open by inflating with extra water. They do this by pumping K+ ions into the cell, which causes water to rush in via osmosis to diffuse the high ion concentration.
11 C. Plants find a use for Transpiration Slide # 11Transpiration: lossof excess water from plant leaves2. Significance:Transpiration causes enough pressure to help pull water (& required nutrients) up stem from roots.As part of the water cycle, trees transpire water back into the atmosphere.Transpiration provides much of the daily rain in rainforest.ABA average size maple tree can transpire 200 liters of water per hour during the summer.Transpiration is the #1 driving force for pulling water up stems from roots.
12 Structure of a Flower 1.Pistil:female reproductive structure Slide # 12FilamentAntherStigmaStyleOvaryPistilPetalSepalOvuleStamen1.Pistil:female reproductive structureStigma: sticky tip; traps pollenStyle: slender tube; transports pollen from stigma to ovaryOvary: contains ovules; ovary develops into fruitOvule: contains egg cell which develops into a seed when fertilized
13 Structure of a Flower Stamen: male reproductive structure Slide # 13FilamentAntherStigmaStyleOvaryPistilPetalSepalOvuleStamenStamen: male reproductive structureFilament: thin stalk; supports antherAnther: knob-like structure; produces pollenPollen: contains microscopic cells that become sperm cells
14 Structure of a FlowerSlide # 14FilamentAntherStigmaStyleOvaryPistilPetalSepalOvuleStamenSepals: encloses & protects flower before it bloomsPetals: usually colorful & scented; attracts pollinators
15 Cross Pollination How does pollination happen? Slide # 15Cross PollinationHow does pollination happen?Pollen from an anther is caught by the stigma, travels through style to the ovules in the ovary.What is the result of pollination?A Fruit: An ovary containing seeds.
16 Plant Responses and Adaptations Slide # 16Chapter 25PlantResponsesandAdaptations
17 Hormone Action on Plants Hormone-producingcellsHormone Action on PlantsSlide #17A. Plant cells can produce hormones: which are chemical messengers that travel throughout the plant causing other cells called target cells to respond.B. In plants, hormones control:Plant growth & developmentPlant responses to environmentMovementof hormoneTargetcellsCells in one blooming flower signals other blooms using hormones to open.
18 C. Plant cells will send signals to one another to tell them: Slide # 18C. Plant cells will send signals to one another to tell them:When trees to drop their leaves.When to start new growth.When to cause fruit to ripen.When to cause flowers to bloom.When to cause seeds to sprout.Leaf DropTree BuddingFruitRipeningCactusBloomingSproutingCorn Seeds
19 D. Ethylene causes Fruit to Ripen Slide # 19D. Ethylene causes Fruit to RipenFruit tissues release a small amount of ethlyeneCauses fruits to ripen.As fruit become ripe, they produce more and more ethlyene, accelerating the ripening process.Ethylene released by apples and tomatoes causes fruit to age quickly.
20 Slide # 20Plant Tropisms1. Tropism: the way a plant grows in response to stimuli in the environment.Phototropism: growth response to light-Plants bend towards lightGeotrophism: growth response to gravity-plant roots grow down with gravity, shoots (stems) grow up against gravity and out of the soil.Thigmotropism: growth response to touch-vines grow up around trees, venus flytrap closes when leaves are touched
21 Thigmotrophism Phototropism Thigmotrophism Slide # 21What type of tropism is shown in these pictures?PhototropismGeotropismThigmotrophismPhototropismGeotropismThigmotrophism
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