2 Systems 3 Tissues 2 Meristems Photosynthesis Growth Reproduction Plant Biology

Plant Body Systems Two types of systems: Root System Shoot System: stem, leaf, flower Plant organs: root, stem, leaf, flower referred to as plant parts

Root System Function Anchorage Absorption Storage Keeps plant in the soil Prevents soil erosion Holds stem in place Absorption water dissolved minerals Storage Starch Other nutrients

Types of Roots http://www.bio.miami.edu/dana/pix/taproot_fibrousroot.jpg http://kentsimmons.uwinnipeg.ca/2153/rootsystems1.jpg http://tchefty.wikispaces.com/file/view/rootsystems1.jpg/260637884/rootsystems1.jpg

Taproot Large long primary root Penetrate deep into the ground Small thin roots grow laterally off main root Strong anchoring system Examples: evergreen trees

Taproot Specialized to store water, food, nutrients Better chance at drought survival Examples: carrot, beet, turnip, radish http://www.ontarioweeds.com/media/jpg/tropr_root.jpg

Fibrous Root Many small roots that branch Increases surface area Better absorption of water and minerals Less structural support Examples: peas, beans, lettuce

Root Hairs Small fibrous objects that branch off roots Absorbs water and minerals

Root Zones Zone of maturation: cells differentiate into different types of cells Zone of elongation: allows the root to get deeper within the soil Meristematic region: rapid mitosis of undifferentiated meristematic cells Root cap: protects the meristematic region

Shoot System Stem Leaf Flower

Stem Raises and supports branches, leaves and flowers Transport of water and nutrients In trees the main stem is the tree trunk http://www.pxleyes.com/images/contests/bw%20tree%20trunks/fullsize/bw%20tree%20trunks_4b6283790291c.jpg

Stem Young green stems can perform photosynthesis because they have chloroplast in their epidermal cells

Stem Some are specialized for food storage Examples: sugar cane, potatoes Stem http://upload.wikimedia.org/wikipedia/commons/9/96/Sugar_Cane.jpg

Leaf Main function: Photosynthesis Parts of the Leaf: Cuticle Epidermis Guard Cells & Stoma Palisade cells Spongy Layer Vascular Tissue

Epidermis Outer layer of cells Leaf epidermis produces cuticle http://www.goldiesroom.org/Multimedia/Bio_Images/05%20Nutrition/15a%20Cross%20Section%20of%20a%20Leaf.jpg

Cuticle Waxy substance that coats the exterior Water proofing Protect interior tissues Blocks passage of gases http://www.goldiesroom.org/Multimedia/Bio_Images/05%20Nutrition/15a%20Cross%20Section%20of%20a%20Leaf.jpg

Guard Cells & Stoma Stoma (Greek for “mouth”) Pore-like openings in the plant’s epidermis Opening size controlled by two guard cells permits gas exchange between the leaf’s interior and external environment. larger opening, faster gas exchange

Guard Cells & Stoma

Spongy Layer Where water is stored Where the vascular tissues reside

Palisade Cells Contains many chloroplast for photosynthesis Cells stand tall and upright Top end exposed to light Bottom end exposed to the gases in the spongy layer

Chloroplast Structure Thylakoids are flat disc-like structures where chlorophyll is embedded Grana are thylakoids arranged in a stack Chlorophyll is a pigment that captures light energy

CO2 + H2O + energy  O2 + glucose Chloroplast Function Site for starch (a type of sugar) storage Site for photosynthesis Reaction involves trapping light energy to create food in the form of sugars Starting substances are carbon dioxide and water CO2 + H2O + energy  O2 + glucose

Leaf Cross Section Scanning electron microscope image of a leaf from a Black Walnut tree. (Dartmouth Electron Microscope Facility/Dartmouth College) http://cache.boston.com/universal/site_graphics/blogs/bigpicture/micro_11_14/m04_walnut_leaf.jpg

Modified Leaf: Cactus

Poinsettia Leaves

Flower Specialized structures developed for sexual reproduction known as pollination Can contain both male and female reproductive structures in the same flower

Flower Parts Male reproductive organ: stamen Female reproductive organ: pistil http://www.exploringnature.org/graphics/teaching_aids/flower_parts_color72.jpg

Flower Parts Male gametes: pollen grains found on anther Female gametes: ovule housed in ovary

Pollination Act of sexual reproduction in plants Pollen reach stigma, travel down the style into the ovary to fertilize the ovule

Methods of Pollination: Wind Pollen grains blown by wind Plants are often small and drab but produce a large amount of pollen Example: grass http://www.vcbio.science.ru.nl/images/pollen/pollen-grass-stigma.jpg

Methods of Pollination: Animals Pollinators: Animals: birds, bats, and on fur of land animals Insects: bees Plants attract pollinators with: Large, colourful fragrant flowers nectar http://4.bp.blogspot.com/_Xla0E3fwLto/S4CL_NstZuI/AAAAAAAABP4/PgoWyz-Mk2w/s400/4342259001_e10572466d_b.jpg

Methods of Pollination: Animals Example: Dandelion plant attracting bees http://guelph.ca/uploads/Healthy%20Landscapes/Pollination_Bee_Dandelion_Zoom.jpg

After Pollination Zygote (fertilized egg) becomes the seed Ovary becomes the fruit

After Pollination Zygote (fertilized egg) becomes the seed Ovary becomes the fruit http://www.biosci.ohio-state.edu/~plantbio/osu_pcmb/pcmb_lab_resources/images/pcmb101/flwrs_sds_frts/where_fruit.jpg

After Pollination http://greatneck.k12.ny.us/gnps/shs/dept/science/krauz/bio_h/images/38_09FruitDevelopment_L.jpg

Plant Tissue Dermal Tissue Vascular Tissue Ground Tissue

Dermal Tissue Outermost layer of a plant Epidermis: thin layer of cells that covers the surface of leaf, stem and root Periderm tissue: bark on stem and large roots of woody plants (replaces the epidermis)

Dermal Tissue Some dermal tissues have unique functions Root cells: root hairs (long extensions) Leaf cells: produce cuticle

Vascular Tissue Plant circulatory system Vessels that connect roots to leaves Transports water, dissolved minerals, and sugars throughout plant, providing cells with materials to carry out life functions Two types: Xylem Phloem

Vascular Tissue: Xylem made up of long hollow tubes formed by non-living cell walls (left over from plant cells that have died) transports water and dissolved minerals upwards from roots

Vascular Tissue: Phloem Made up of elongated cells that are living Transports: solutions of sugars (food) Dissolved nutrients Hormones Bi-directional movement of materials downward to roots upward to leaves

Vascular Bundle

Plant Sugars Starch is NOT soluble in water Starch can be broken down into sucrose Sucrose IS soluble in water Sucrose is transported through the phloem to the plant parts that require it Sucrose can be broken down into glucose Glucose is used in cellular respiration to make cellular energy Starch  sucrose  glucose

Spring Trees need energy to grow leaves Energy comes from cellular respiration of glucose: Glucose + oxygen  carbon dioxide + water + energy Glucose can be obtained by: Photosynthesis - but spring trees don’t have any leaves to do photosynthesis Converting it from starch

Spring Starch Sucrose Glucose Stored in the roots Insoluble in water so it cannot be transported through phloem Convert to sucrose Sucrose Soluble in water Transport from root to tree bud through phloem Convert to glucose in tree bud Glucose Use in cellular respiration Converted to cellular energy needed to grow leaves

Tree Sap Starch Sucrose Glucose Roots Stem Leaves Storage Transport Photosynthesis

Plant Sugars Sugar Solubility in water Location Function Starch No Root Storage Sucrose Yes Stem Transport Glucose Leaf Cellular respiration

Summer Once leaves have grown, they can perform photosynthesis to produce their own glucose Glucose is converted to sucrose and transported through the phloem to the roots Sucrose is converted to starch in the roots for storage

Sugar Movement through Phloem Glucose (leaves) Sucrose (stem) Starch (roots) Winter storage Spring Summer and Fall Spring Summer and Fall http://www.nuscentscandle.com/blog/wp-content/uploads/tree-sap.jpg

Cells in the Root Cells in the root have no chloroplasts and are not exposed to sunlight so they can not undergo photosynthesis to make their own food Root cells must perform cellular respiration to obtain cellular energy Glucose + oxygen  carbon dioxide + water + energy Glucose comes from the starch stored in the root Oxygen is absorbed through the soil

Ground Tissue Filler tissue in between the dermal and vascular tissue Variety of processes depending on where it is in the plant In leaf: palisade and spongy mesophyll cells