mineral particles

decomposing organic matter

air

water

living organisms 

< 0.002 mm

-high water holding capacity, not all water available for plant

- 

sand

silt

-even mixture of particle size

-best soil for agriculture 

weathering of parent material

(bedrock) 

(organic)

-organic, few cm thick 

-humus, organic decay products

-contained within A horizon 

-topsoil, 10-30 cm

- greatest physical, chemical, and biological activity 

-subsoil, larger particles, 30-60cm leaching from A horizon by water percolation

- iron oxide, clay particles, less O. material ?

-mixed with A horizon when plowed 

C horizon

-soil base

partially weathered parent material, 90-120 cm 

Soil Forming Factors

-parent material

-cliamte

-living organisms

-topography 

-time 

What do plants NOT obtain from topsoil? 

-CO2 

How many nutrients are essential for healthy plant growth? 

-16 

Essential Elements 

-required for normal growth and reproduction

- no other element can replace

- direct or indirect action in plant metabolism 

Macronutrients 

-required in greater amount 

C,H,O - basic organic constituents

N, K, Ca, P- amino acids, nucleotides, ATP, NADPH, cell wall, regulatory, osmoregulation

-Mg, S - chlorophyll, electron transport chain, amino acids 

Chlorosis 

-Magnesium and Iron deficiency 

Micronutrients 

-required in lesser amounts

-Fe, Mn, Cu, Zn, b, Mo, Cl, Ni

-essential for enzyme function, organ & organelle function, photosynthesis 

Proportional weightof Various elements in plants 

C, H, O - 96%

other macro - 3.5%

micronutrients - 0.5% 

what percent of plant biomass is roots? 

50% 

What do roots do?

-anchorage, storage, absorption, condusction 

Roots compared to animals? 

-Roots are how plants "forage" for dilute nutrients in environment 

What is the first root formed? 

the radicle 

taproot system 

-in dicots, radicle grows into taproot

- branch roots grow from taproot 

Fibrous root system 

-mostly in monocots

- extensive mass of similarily sized roots

- radicle short-lived, replaced by adventitious root system 

what is adventitious? 

-not belonging to

-roots grow from stem 

root cap 

-protection from dessication, lubrication, water and nutrient absorption 

-zone of cellular division 

-densely packed cells undergoing mitosis 

- zone of elongation 

-growing cells 

zone of maturation 

-differentiating cells 

Epidermis     

one cell thick, usually no cuticle, absorbs water 

Cortex   

just interior to epidermis, waxy protective layer

parenchyma tissue, mots of cortex, often contains starch

enderdermis tightly packed cells with casparian strip 

Stele 

-tissue inside cortex

-pericycle: interior to endodermis- a meristem for branch roots

-vascular bundle: xylem as a cross with phloem in armpits

The cortex of the root is formed by which primary meristem? 

Ground meristem

Casparian Strip 

-integral band-like portion of pirmary wall and middle lamella in endodermal cells

Sympastic movement

move through endodermal cells

Apoplastic movement 

- move through intracellular space 

Unique properties of water

(due to molecular strcuture) 

-  hyrdogen bonding

-cohesion and adhesion

-capillarity 

capillarity 

-from cohesion and adhesion 

transpiration 

-water loss through the leaf 

What percentage of plant is water? 

85% to 95%

What percentage of water from roots in transpired back into atmosphere?

- 95% 

In what pattern does xylem grow? 

Outside - in 

Through what openings does water leave the plant? 

-Stomata 

Cohesion-tension theory 

- as water evaporates from the leaf surface, a column of water is pulled upward from the soil water 

What makes up xylem tissue? 

-Vessel elements and tracheids 

What xylem tissue characterizes gymnosperms and ferns? 

trachieds 

What kind of xylem tissue characterizes angiosperms? 

- vessel elements 

Pit 

- hole in cell wall

- laterally connect tracheids and vessel elements 

What kind of problems can their be with water movement? 

- air bubbles

  - cavitaion and embolism
 

cavitation 

- water column rupture 

 embolism

- filling with air or water vapor

-eventually embolism will occur 

Is there  a limit to the water column? 

122-130 meters may be the limit 

Tallest trees 

Coastal Redwoods 

Coast Redwoos 

circum = 26 feet

diameter= 8 feet 

height = 113 m

est. age  = 2,000+ yrs 

what makes leaves adapted for photosynthesis? 

abundant stomata

large number of vein endings 

Describe trade0ff in transpiration 

CO2 in = photosynthesis

H20 out = transpiration 

Evapotranspiration 

transpiration and soil evaporation? 

Branch Roots 

form from pericycle, not epidermis

pushes through and destroys cork, and epidermis cells 

Where is the cell membrane of a plant located? 

Outside the plasma membrane 

The eukaryotic cell 

-cell wall

-plasma membrane

-cytoplasm

    -various organelles

    - cytoplasmic streaming

-nucleus

-vacuole bound by tonoplast 

Cell wall functions 

constraing protoplast expansion

determine size/shape of cell

contain enzymes, absorb, transport and secrete substances

important role in defense

not just a container boundary 

color of stain produced by primary and secondary

green - primary

red- secondary 

Primary Cell wall 

-outside of  plasma membrane

-deposited during cell growth

-contain thin areas

pits and plasmo.

-shared w/ adjacent cell

-middle lamella 

Chemistry of Primary Cell Walls

cellulose

hemicellulose

pectins

glycoproteins

lignins

cutin

suberin

waxes 

cellulose 

-glucose membranes

-bundled into microfibrils

-wound and coiled into macroribrils 

hemicellulose 

-polysaccharides that limit cell wall etensibility 

Pectins 

- primary cell walls and middle lamella

- give wall pliability; act as cement 

What determines cell growth? 

celluose microfibril orientation 

True or false

the primary cell wall of plants is located inside the plasme membrane?

False

True or False

The secondary cell wall is located inside the primary cell wall? 

- True

Secondary Cell Walls 

-formed inside the primary wall

-very thick

-not present in all cells

-formed after cell growth

-function in strength &H2O trasnport

-abundant cellulose and hemicellulose

-no pectins or glycoproteins- not elastic

abundant lignins - gives rigidity adn hardness 

Examples of Secondary cell wall 

vascular tissue

ground tissue

???????? 

Leaves 

not different tissues from stem, but different arrangement

Leaf epidermis is produced by what?? 

-protoderm 

mesophyll is produced by the.....? 

ground meristem 

vascular bundles are produced by the....? 

-procambium 

True or False

IN leaves, the vascular bundles are called veins? 

True 

Leaf Primordium 

starts as small bulge at apex

looks like batmans head

-it continues to grow and forms procambium which developes into leaf midvein 

Leaf Architecture 

simple leaves - flat, undivided blade, supported by petiole

compund leaves- blade divided into leaflets

pinnately-feather-like

plamately= hand-like 

Internal structure of leaf 

epidermis- compact, transparent, not photsynthetic

vascular tissue - xylem and phloem in veins

                          -supported by bundle sheath fibers

Ground tissue- mesophyll; photosynthetic tissue -chlorenchyma 

True or False

All cells of the epidermis lack chloroplasts? 

False

-gaurd cells have chloroplasts 

Dicot Leaves

ex. cottonwood leaf 

-netted venation

-mesophyll made up of long, slender palisade cells and spongy mesophyll cells

(air space) 

Monocot Leaves 

Parrallel veins

All mesophyll cells

Bulliform cells 

bundle sheath cells 

Bulliform Cells of monocot leaves 

adaptation for protection from heat/ water loss

on upper epidermis

leaf to leaf rolling 

Bundle sheath cells of monocot leaves 

surrounded  vascular bundles

in C4 monocots

True or False

Leaves growing in the sun have higher rates of photosynthesis that shade leaves? 

True 

Environmental Control of leaf Variation 

light intensity differences

-sun and shade leaves 

moisture differences 

-xerophytes and hydrophytes 

What is the greatest problem faced by plants growing in dry areas? 

sun and wind exposure, limited water, increased ET 

What is the greatest modified structure in the leaf anatomy of a desert plant? 

epidermis