Upload
jagger-jacklin
View
229
Download
5
Tags:
Embed Size (px)
Citation preview
Basic plant anatomy 1
A. root– root tip-roots grow
at the tip – root hairs-
increase absorptive surface area
Roots • Roots anchor plant in soil, absorb
minerals & water, & store food– fibrous roots (1)
• mat of thin roots that spread out• monocots
– tap roots (2)• 1 large vertical root • also produces many small lateral,
or secondary roots • dicots
– root hairs (3)• increase absorptive
surface area
2
1
3
Basic plant anatomy 2B. shoot (stem)
– Nodes-where leaves attach• Internodes-space
between nodes
– Buds• Meristems are where
plant shoots grow• terminal or apical buds
at top of stem• axillary buds- at base of
leaf on stem• flower buds-produce
flowers
Basic plant anatomy 3
C. leaves– Cuticle- waterproof layer– Epidermis- covers top &
bottom surface– mesophyll tissue
• Palisade- columnar cells, with choloroplasts just below upper epidermis
• Spongy- irregularly shaped cells with air spaces between them below palisade
– veins (vascular bundles)
Leaves• Function of leaves
– photosynthesis• Traps solar energy• Produces sugars (food)
– gas exchange- occurs through pores called stomates
• Guard cells open or close stomates-depends on water
– Transpiration- water loss through the stomates
Plant adaptations
1. Roots- – Tap root-used for food storage (carrot)
2. Stems-rhizomes (iris) & stolons (strawberry)- used to
make new plants- tubers- (potato) used for storage- Bulbs- (onion) buds used for storage & new
plants
Plant adaptations3. Leaves• CAM & C4-photosynthesis- chemical
adaptation for plants in hot climates• Enlarged darker leaf-jungle plants-low light• Spines & poisons- defense against
herbivores• Thickened leaf- water storage• Tendrils- climbing plants- attach & support• Bright colors- leaves doing job of petals
• Both systems depend on the other– roots need sugars
produced by photosynthetic leaves
– shoots need water & minerals absorbed by roots
Interdependent systems
water &minerals
sugars
Vascular tissues
• Xylem – move water & minerals up from roots – dead at maturity
• only cell walls remain• transpirational pull hauls water up from roots
Phloem: food-conducting cells • carry sugars & nutrients throughout plant• sieve tube elements – Living at maturity
– Keep cell membrane & cytoplasm– lose their nucleus & organelles– sieve plates — end walls — have pores to
allow flow of food between cells
• companion cells- attached to sieve tubes– run the cell- have nucleus & cell structures
Putting it all together • Obtaining raw materials
– sunlight• leaves = solar collectors
– CO2
• stomates = gas exchange
– H2O• uptake from roots
– nutrients• uptake from roots
Growing Cycles
• Perennials - live several years, and reproduce many times Ex. woody plants
• Annuals - plant that completes its life cycle in one growing season (grows, flowers, reproduces and dies)
• Biennials - take two growing seasons to complete, reproduces in the second growing season
Growing Cycles
• Plants grow only at their tips in regions called MERISTEMS
• PRIMARY GROWTH makes a plant taller at roots and stems
• SECONDARY GROWTH makes a plant wider, or adds woody tissue
How Old Is That Tree?• Tree Rings tell age of a tree,
each ring for one growing season.This tree is 4 yrs old. – Spring wood- lighter colored,
larger tubes– Darker colored, narrower
tubes
• VASCULAR CAMBIUM: makes xylem and phloem and forms the annual rings
Monocots & dicots• Angiosperm are divide into 2 classes
– dicots (eudicot)• 2 cotyledons (seed leaves)• leaves with network of veins• woody plants, trees, shrubs, beans
– monocots• 1 cotyledon• leaves with parallel veins• grasses, palms, lilies
Simple Tissues – consisting of one cell type
• Parenchyma – thin walled & alive at maturity; cells take different shapes. (storage, can change into other cells)
• Collenchyma – thick walled & alive at maturity (support)
• Sclerenchyma – thick walled and dead at maturity (support)– Sclerids or stone cells – cells that are as
long as they are wide, very heavy cell walls– Fibers – cells longer than they are wide