USFCA Archambeault Plant Nutrition and Transport

Three types of plant tissues

dermal, ground, vascular

Dermal Tissue Function

Protects shoot system
Allows for water & nutrient absorption by root system

Ground Tissue Function

functions in photosynthesis & carbohydrate storage and support

Vascular Tissue Function

Functions in support &
transport of materials within
a plant

Epidermal

Secretion of the cuticle, defense

Guard Cells

open and close stomata

3 Cell Types of Ground Tissue

sclerenchymal, parenchymal, collenchymal

Parenchymal

"workhorse" cells
Responsible for photosynthesis in leaves and starch storage in roots.

Collenchymal

Shoot support for growing plant parts.
Secondary cell wall is a structure between plasma membrane and primary cell wall.
Contains cellulose and primary cell wall

Sclerenchyma

Rigid structural support. for the cell wall
No mature cells, therefore do not expand, support plants that are dead.

Two Tissue Types of Vasculat Tissues

Xylem, Phloem

xylem

Have secondary cell wall containing lignin
Two cell types:
1)Tracheids: found in all vascular plants; long and slender
2) Vessel elements: found only in angiosperms; shorter, wider cells
Pits are areas lacking secondary wall- they line up with neighboring cell to allow for water exchange
Perforations are gaps that allow for free passage of water

Phloem

No secondary cell wall
Two cell types:
1)sieve-tube elements: long and thin perforated ends that transport sugars and nutrients. Lack nuclei and most organelles.
2)Companion cells: not conductive, sustain sieve-tube cells through gaps in cell walls called plasmodesmata

2 forms of plant growth

Determinate Growth, Indeterminate Growth

Determinate Growth

stop growing after reaching a certain size
Leaves, thorns, flowers

Indeterminate Growth

grow throughout lifespan

2 types of Indeterminate Growth

Primary growth: increase length of shoot and root systems
Secondary growth: increases the width of plants

Primary Growth: Growth in Length

growth in length
Meristems are the populations of dividing unspecialized stem cells
Apical Meristems:
Located at the tips of shoots and roots
Give rise to three cell types:
- Dermal tissue from protoderm
- Ground tissue from ground meristem
- Vascular tissue from procambium

Three zones of meristem:
-zone of division
-zone of elongation
-zone of differentiation

Secondary growth: growth in width
-Only in woody plants

Increases width of plants
provides additional structural support

Increase amount of conducting tissue(xylem and phloem)

Lateral meristems: Single layer of meristematic cells that form a cylinder

Runs along the length of stems and roots
They become active only when primary growth has ceased in that area

A stem or root thickens as secondary xylem, secondary phloem, and dark cells are added in rings.

Two types:
Vascular cambium Forms: secondary phloem & xylem
Cork cambium Forms: cork cells
Bark = cork cells + secondary phloem

Wood Composition

Is composed of secondary xylem produced by vascular cambium
Heartwood:
It is present center of the tree and provides support
Forms inner secondary xylem that is inactive (does not transport water)
Sapwood:
portion of secondary xylem that transports water.
Bark:
all the tissues that are exterior to the vascular cambium
Includes secondary phloem, cork cambium, and cork