505 system classification

Plant system

Stem

Leaves

roots

flowers

buds

Stem

structure

vascular flow

storage , (photosynthesis)

Leaves

photosynthesis

gas exchange

material movement

roots

structural

water and nutrient uptake

storage

anchor

flowers

reproduction (spread pollen and genetics further)

seeds to create offspring

buds

lateral shoots from erect stems, new shoots from rhizomes and tubers

buds typically form in very consistent differences, root development is random

the system can be shifted by weeds

weeds have advantages with each part of its system

plant tissues

vascular tissues

• xylem

• phloem

structural

epidermal

xylem

dead cells

driven by transpiration

• makes it one directional

• no energy required

ligning reinforcment

water and some minerals

phloem

phloem is more porous and provides no structural support

transports sugars aa

requires energy

bi-directional to sinks

structural tissue

make up the majority of the plant

• parenchya, schlerenchyma and collenchyma

• act as filler tissue

  • site of photosyntheiss (specialized perenchyma)

epidermal tissue

outer waxy layer- cuticle

protects the plant from minor damage and excessive water loss

certain cells of the root epidermis form root hairs

• increases surface area for water and mineral uptake

plant growth

division

enlargement

differentiation

growth occurs from what meristematic regions

apical

buds

root apical

pericycle

leaf margins

vascular cambium

cork cambium

intercalary meristem

stem apical meristem

increases stem length, leaf formation, buds and flowers

buds

formation of lateral shoots or flowers

root apical meristem

increases root length

pericycle

formation of lateral rootsle

leaf margins

increase leaf width

vascular cambium

increase both stem and root diameter in broadleaves

cork camium

produces cork cells in woody stems and roots (bark)

intercalary meristem

located at base of each grass internode; increases length of stem in grasses

plant development

the pattern in which cells differentiate are incorporated into tissues, and tissues combined into organs, results in the final form of the plant and accounts for the variation in structure among species

first structure to emerge from the seed is the radicle root followed quickly after stem tip

BROADLEAVES

first internodal cell (hypocotyl, epicotyl) expand rapidly

food material comes from cotyledons until the first leaves begin photosynthesizing

cotyledon size on growth rate

depends a lot on environmental conditions not necessarily all competitive abilities

grass plant development

coleoptile is the first structure to merge

developing leaves bread the the coleoptile and unfurl

internodal regions do not elongate immediately; the stem tip remains close to the ground for an extended period of time

why stack more leaves early

• energy early

• competitive ability

why elongate later

• dispersal

• pollination

transport pathways

aploplastic

symplastic

aploplastic pathway

major pathway for water and minerals

movement from soil upwards

more or less continuous system of cell walls, spaces outside of plasma membrane, intercellular spaces and nonliving tissue

physical process of transpiration

driven to xylem

symplastic pathway

major pathway for sugars

movement from source to sinks

more or less a continuous system of protoplasts in plant cells and includes living tissues

diffusion gradient is critical for transport

tied to phloem