Upload
thelawofscience
View
4.465
Download
6
Tags:
Embed Size (px)
Citation preview
2 Systems3 Tissues2 MeristemsPhotosynthesisGrowthReproduction
Plant Biology
Plant Body Systems
Two types of systems:Root SystemShoot System: stem, leaf, flower
Plant organs: root, stem, leaf, flower referred to as plant parts
Root System Function Anchorage
Keeps plant in the soil
Prevents soil erosion Holds stem in place
Absorption water dissolved minerals
Storage Starch Other nutrients
Types of Rootshttp://www.bio.miami.edu/dana/pix/taproot_fibrousroot.jpg
http://tchefty.wikispaces.com/file/view/rootsystems1.jpg/260637884/rootsystems1.jpg
http://kentsimmons.uwinnipeg.ca/2153/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 areaBetter absorption of water
and mineralsLess structural supportExamples: 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
StemLeafFlower
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
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
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
Chloroplast Function
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: stamenFemale 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 plantsPollen reach stigma, travel down the
style into the ovary to fertilize the ovule
Pollen grains blown by wind
Plants are often small and drab but produce a large amount of pollen
Example: grass
Methods of Pollination: Wind
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 beeshttp://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 plantEpidermis: 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 systemVessels that connect roots to leavesTransports 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 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 TransportPhotosynthesi
s
Plant Sugars
SugarSolubilityin water
Location Function
Starch No Root Storage
Sucrose Yes Stem Transport
Glucose Yes Leaf Photosynthesis
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
Glucose
(leaves)
Sucrose
(stem)
Starch
(roots)
Winter storage
Summer and Fall
Summer and Fall
Spring
Spring
Sugar Movement through Phloem
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