Download CH 29 30 - Liberty Union High School District

Plant Anatomy,
Growth, Transport, and Nutrition
[Ch 29 and 30]
AP Biology
Anatomy
1. Root
2. Shoot
3. Leaves
AP Biology
2005-2006
Roots
 Purpose: anchor, absorb minerals and water,
store food
Adaptation  Root hairs to increase SA for
absorption
AP Biology
Shoot  stems and buds
Purpose: growth and transport
Stems
• node = site of leaf attachment
Buds
• terminal /apical = tip
• axillary = lateral; from node
AP Biology
Leaves
Function:
photosynthesis
 gas exchange
 transpiration

AP Biology
2005-2006
Raw Materials
 sunlight

chloroplasts in leaves
 CO2

gas exchange through
stomata
 H 2O

roots
 nutrients

AP Biology
roots
Interdependence
 ROOTS get sugar &
sugars
nutrients from
photosynthetic parts
[shoots]
 SHOOTS depend on
water & minerals
absorbed by roots
water
AP Biology
2005-2006
3 Plant Tissues
1. Dermal
[skin]
covers & protects
2. Vascular [transport]
movement between roots
& shoots  xylem &
phloem
3. Ground [bulk of plant]
storage, photosynthesis
AP Biology
Vascular tissue [tube shaped cells]
 Transport in roots, stems & leaves
 Xylem


water & minerals
dead cells
 Phloem


Nutrients like sugar
living cells
AP Biology
2005-2006
Growth

annuals
 life cycle 1 year

perennials
 lives many years
AP Biology
Transport in plants
 H2O & minerals


xylem
transpiration
 Sugars


phloem
bulk flow
 Gas exchange

photosynthesis
 CO2 in; O2 out
 Uses stomates

Cellular respiration
 O2 in; CO2 out
 roots exchange gases
within air spaces in soil
AP Biology
Cellular Transport
short-distance transport
 cell to cell
long-distance transport (bulk flow)
 throughout whole plant in xylem and
phloem
AP Biology
LONG DISTANCE
 Bulk flow = movement by pressure
 xylem
 Negative pressure
 Transpiration pulls sap up from roots

phloem
 Positive pressure
 Sugar from leaves pushes sap through
tube
AP Biology
Water Potential
Flaccid
wilt
Turgid
swollen
AP Biology

osmosis through
aquaporins

water moves high to low
Mineral & Water uptake by roots
 Mineral uptake


active transport pumps minerals in
concentration gradient established [salt sucks]
 Water uptake  by root hairs


AP Biology
high to low
root pressure
Mycorrhizae
Symbiotic relationship between FUNGI &
PLANTS

AP Biology
increases SA for absorption of water & minerals
Rise of water in a tree by bulk flow
 Transpiration pulls water by
adhesion & cohesion

H bonding
 Water potential

high in soil  low in leaves
 Root pressure push


H2O from soil to roots
upward push
AP Biology
Transpiration
Water loss from leaves [90%]
 Stomates  openings on underside of
leaves

Balancing act
 Close = prevents water loss
 Open = CO2 in for photosynthesis
AP Biology
Regulation
 Guard Cells control
stomata


Full of water = open stomata
Empty = close stomata
 K+ Role in Guard Cells

K+ ions enter guard cells
 Proton Pumps
 Causes H2O to enter
 Turgid  OPEN

loss of K+ ions from guard
cells
 H2O exits
 cells flaccid  CLOSE
AP Biology
Transport of sugars
 active transport of sucrose
 Phloem
 proton pumps  gradient pulls in water and
causes FLOW
AP Biology
Nutritional needs

plants need…
 sun
 inorganic compounds
 water (H2O)
 CO2
 Minerals like Mg, Na, Zn, etc
AP Biology
Magnesium deficiency
 Symptoms
chlorosis = yellowing of leaves
 Mg needed to make chlorophyll

AP Biology
Nitrogen Cycle
 nitrogen fixation (N2  ammonia  nitrates)
 Bacteria FIX nitrogen
root
AP Biology
Legumes
 Symbiotic relationship between bean plants and bacteria


They FIX nitrogen into usable form for plants  nitrates
Animals & Fungi get nitrogen from food they eat
AP Biology