Trees and Tree Parts

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Trees and Tree Parts
The baobab tree (Adansonia digitata) of Africa
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Where Life Begins Cells

• Cells are composed of
• Organelles, which are composed of
• Molecules, which are composed of
• Atoms, which are composed of
• Neutrons, electrons, protons
• Only cells are alive.?
• Organization!!

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Where Life Begins Cells

• The Second Law of Thermodynamics
• The natural state of the universe is
• DISORDER!!!
• (entropy)
• Your body (and all living things) want to resist
  change.resist becoming atoms.

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The Laws of Thermodynamics

• (You dont need to know these.)
• For every action, there is an equal and opposite
  reaction. (Newtons Law)
• The natural state of the universe is disorder.
• (Entropy)
• Matter is neither created nor destroyed.
• (Conservation of Mass)

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Where Life Begins Cells

• Eukaryotic vs Prokaryotic Cells
• Prokaryotic - no nucleus, typical in bacteria
• Eukaryotic - nucleus, typically multicellular

Which type of cell do trees have?
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A Eukaryotic Plant Cell
cell wall
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Where Trees Begin Germination
Step One Radicle Forms
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Germination
Step Two Cotyledon Forms
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Germination
Step Three Leaves Form
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Monocot vs. Dicot
hypogeal growth
epigeal growth
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Other Comparisons

• Gymnosperm vs. Angiosperm

GymnoconeSpermseed
AngioflowerSpermseed

• Perennial vs. Annual

Annualyear (completes life cycle each
yearonly lives one year)
PereachEnnialyear

• Tree vs. Shrub vs. Herbaceous Plant

Trees have one central woody trunk shrubs have
multiple woody trunks

• Deciduous vs. Evergreen (not always Coniferous)

Loses leaves
Doesnt
Cone-bearing
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Some Tree Pics
Dawn Redwood (Metasequoia glyptostroboides)
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Some Tree Pics
Banyan (Ficus benghalensis)
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Some Tree Pics
Red Mangrove (Rhizophora mangle)
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Some Tree Pics
Baobab (Adansonia sp.)
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Some Tree Pics
Sausage Tree (Kigelia pinnata)
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Some Tree Pics
Pencil Tree (Euphorbia tirucalli)
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Some Tree Pics
Bald Cypress (Taxodium distichum)
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Roots Nutrient Availability

• Roots serve severalimportant functions
• Conduct water and nutrients to the leaves
• Anchor plants to ground
• Store food supplies as starch

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Types of Roots
Agapanthus africanus
Passiflora sp.
Daucus carota
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Dicot Root Long. Section

• Apical Meristem
• Root Hair

• Root Cap - Dead cells

up
down
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Dicot Root Cross Section

• Find the following
• Xylem
• Phloem
• Vascular Bundle
• Pericycle
• Endodermis
• Cortex
• Cork Cambium
• Vascular Cambium

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Dicot Root Cross Section

• Find the following
• Xylem
• Phloem
• Vascular Bundle
• Pericycle
• Endodermis
• Cortex
• Cork Cambium
• Vascular Cambium

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Leaves Photosynthesis

• Leaves serve severalimportant functions
• Photosynthesis
• Protect chloroplasts from sun
• Moves rainwater to roots (drip tips)

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Leaf Cross Section

• Find the following
• Mesophyll
• Palisade Tissue
• Spongy Tissue
• Vein
• Xylem
• Phloem
• Guard Cell
• Stomate
• Upper Epidermis
• Lower Epidermis
• Cuticle
• Chloroplast

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Leaf Tissues

• Mesophyll
• Spongy Tissue- allows gas exchange to Palisades
• Palisades- center of Photosynthesis
  (Chloroplasts)
• Stomata
• Guard Cells regulate gas and H2O
• Must be open to allow CO2
• Must be closed to avoid drying out
• VPD- closer to zero is better (humidity)
• Vapor Pressure Difference H2O outside leaf
  - H2O inside leaf

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Vapor Pressure Difference

• When is VPD high?
• Why might this be a problem for plants?
• What replaces water in the leaves?
• Water and Nutrients from the roots.
• When is VPD low?
• What types of plants live in this environment?
• Cacti store CO2 at night for use during the
  day

H2O outside - H2O inside
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Dicot Leaf Sections
Lilac (Syringa vulgaris)
Coleus (Coleus sp.)
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Monocot Leaf Sections
Corn (Zea mays)a grass
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Photosynthesis

• Light H2OCO2Nutrients Oxygen Glucose
• Light Dependant Phase
• Visible light has many wavelengths (680 700)
• PSI-captures light at 700nm
• -releases 2 electrons to bind NADP to H
• PSII-captures light at 680nm
• -releases 2 electrons (e-) to PSI
• -gathers new electrons from H2O
• -2H2O splits to O2, 2H, and 2e-

NADPH
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Photosynthesis

• Light H2OCO2Nutrients Oxygen Glucose
• Light Independent Phase
• Calvin Cycle run by NADPH and RuBP
• RuBP binds with CO2 from stomata
• Molecular rearrangement to glucose (C6H12O6)
• Generates NADP, RuBP, O2, and C6H12O6

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Photosynthesis

• Light H2OCO2Nutrients Oxygen Glucose

2e-
NADPH
RuBP
Photosystem I
Light
NADP
H
2e-
O2
Calvin Cycle
CO2
Photosystem II
Water
Glucose
O2
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SPACSoil - Plant - Air - Continuum

• Transpiration - how water moves from roots to
  leaves
• H2O moves out of leaves
• Absence draws H2O from soil into roots
• Osmosis - water moves naturally from where there
  is more to where there is less
• Osmosis controlled by salts in trees
• More salt in cells draws water into the tree