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Systems: Roots and ShootsPlant Parts: root, stem, leaf, flowerPlant Biology Part 1 -
Systems
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.jpghttp://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 ZonesZone 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 – structure and transportLeaf – photosynthesis Flower – reproduction
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
StemSome are specialized for food storageExamples: sugar cane, potatoes
http://upload.wikimedia.org/wikipedia/commons/9/96/Sugar_Cane.jpg
4 Types of Modified Stem
StolonRhizome
TuberBulb
Modified Stem: Stolon Grow on surface of ground
horizontally Enable plant to colonize
large areas asexually from a single parent
Example: Strawberry runners
http://plant-passion.typepad.com/.a/6a00e551cf6c9a88330120a5344f62970b-pihttp://strawberryplants.org/wp-content/uploads/2010/05/strawberry-plant-runners.jpg
Modified Stem: Rhizome
Horizontal growth underground (an underground stolon)
Example: Edible base of ginger planthttp://nogmoseedbank.files.wordpress.com/2010/10/zingiberofficinale-thum.gif
Modified Stem: Tuber Swollen ends of
rhizomes specialized for food storage
Example: potato, yam, taro, cassava, sweet potato
http://database.prota.org/dbtw-wpd/protabase/Photfile%20Images/Adenia%20digitata%20tuber%20B.%20Wursten.jpg
Adenia digitata is poisonous. The Tswana people of Botswana have used the fruit for homicide. Accidental poisoning mainly occurs when the root of Adenia digitata is mistaken for edible tubers. To treat skin ailment, leprosy or ulcers, the Nyanja people of Malawi and Zambia rub the skin with boiled roots or a root decoction.
Modified Stem: Bulb
Vertical underground swollen base Example: Onion bulb
http://4.bp.blogspot.com/-YTxeUV00GQI/TbFydVLx6WI/AAAAAAAAB7Q/_Ae2T2c1ico/s1600/spring_onionR.jpghttp://69.39.232.84/~ecofrien/oniongardening.com/wp-content/uploads/2007/02/harvestonions.jpg
LeafMain 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 photosynthesisReaction 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 PartsMale 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 plants Pollen 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: Wind
All conifers are non-flowering
Produce male and female pine cones
Use wind to pollinate
http://www.sciencephoto.com/media/17620/enlarge
Methods of Pollination: Animals
Insects, birds, bats
Insects pollinate about 70% of all flowering plants
Crops pollinated by bees provide 30% of human food
Attracting Pollinatorsnectar
http://4.bp.blogspot.com/_Xla0E3fwLto/S4CL_NstZuI/AAAAAAAABP4/PgoWyz-Mk2w/s400/4342259001_e10572466d_b.jpg
Attracting Pollinators
Fragrant flowers (scent)Big Pollen Load
http://guelph.ca/uploads/Healthy%20Landscapes/Pollination_Bee_Dandelion_Zoom.jpg
Attracting Pollinators Large Stigma
Attracting Pollinators
Large Petals
Attracting Pollinators Bright colours
Attracting Pollinators Pollen
guides/indicator
Pollination videos (BBC David Attenborough)Titan Arum’s scent (2:29)
http://www.youtube.com/watch?v=FHaWu2rcP94&feature=related
Hoverfly and pollen guides (2:29)
http://www.youtube.com/watch?v=MQlq5QtRI9o
Orchid mimics female wasps (2:59) http://www.youtube.com/watch?v=-h8I3cqpgnA
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