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Plant Anatomy. Honors Biology. Remember…. Atoms Molecules Cells Tissues Organs Organ systems Organisms. Types of Tissues in Plants. Epidermis Function - Protection. Types of Tissues in Plants. Ground Tissue many functions Food storage Water storage Photosynthesis
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Plant Anatomy Honors Biology
Remember… • Atoms • Molecules • Cells • Tissues • Organs • Organ systems • Organisms
Types of Tissues in Plants • Epidermis • Function - Protection
Types of Tissues in Plants • Ground Tissue • many functions • Food storage • Water storage • Photosynthesis • Think “packing peanuts” • Fills in spaces…
Types of Tissues in Plants • Vascular Tissue • Transports Food and Water through a plant’s body • TWO types of vascular tissue • Xylem • Transports water • Up from roots • Phloem • transports food • Down from leaves • Usually found packaged together within a plant
Types of Plant Tissues • Meristem Tissue • Growing tissue of a plant • LOTS of CELL DIVISION occurs in this tissue (MITOSIS) • Allows the plant to grow in height • Found in the tips of shoots • Found in the tips or roots • Allows SOME plants to grow in width • TREES • Found in a cylinder of tissue that surrounds the trunk of a tree
ROOTS • Functions • Anchor Plant to soil • Obtain water and nutrients from soil • Store food
Roots • Zones of a growing root • Root Cap • Dead tissue • Protects delicate root tip • Zone of cell division • MITOSIS occurs here • LOTS of new cells • SMALL cells – newly formed • Zone of elongation • Cells grow in SIZE • Zone of maturation • Cells take on a particular JOB • Example: Root hair • Increase surface area to take up water
Cross Section through the Middle of a Root • Epidermis • Cortex • Made up mostly of ground tissue • Used for food storage • Vascular Cylinder • Xylem • phloem
STEMS • Functions • Support Leaves • Conduct water and food through the plant • Sometimes store food
Two Main Types of Stems • Herbaceous • Green, soft • Small plants • May be monocot or dicot
Two Main Types of Stems • Woody • Non-green, thicker, harder • Grow in WIDTH, not just length • Cambium – meristem tissue that can grow in width • Located between xylem and phloem • Results in Annual Rings • Usually dicot
Stem Cross Section - DICOT Epidermis Phloem Cortex Xylem
LEAVES • Function • PHOTOSYNTHESIS!
Leaf Structure • Cuticle • Waxy layer – no cells • Secreted by epidermis • Prevents WATER LOSS
Leaf Structure • Epidermis • Single layer of cells • protection
Leaf Structure • Mesophyll • Palisade Layer • Where photosynthesis occurs • BIG cells • LOTS of chloroplasts • Spongy Layer • Gas exchange occurs here • CO2 IN; O2 OUT
Leaf Structure • Lower epidermis • Protection • Control of water loss • Guard cells and stomata found HERE
How Stomata and Guard Cells Work • When conditions are good (lots of water) • Guard cells are TURGID (full of water) • Guard cells OPEN • Allow CO2 in • Water loss is NOT a problem • When conditions are bad (little water) • Guard cells are FLACCID (empty of water) • They CLOSE • Water cannot escape • BUT…CO2 can’t get in… NO PHOTOSYNTHESIS!
Chloroplast Stomata
Plant Activities • Transpiration • Tropisms • Phototropism • Plant grows toward LIGHT • Geotropism • Growth in response to GRAVITY • Root grows DOWN • Stem grows UP Click HERE for Plants in Motion