Plant Tissues
Levels of Organization:
Cells - Tissues - Organs - Organ Systems - Organism - (more!)
Tissues
most are parenchyma (?) -- vascular are most interesting
Xylem
- hollow water tubes
- thick walls
- no cytosol
- no organelles
- Schlerenchyma (dead at maturity)
- conducts water and minerals up from soil year-round
- in spring sap flow, carries sugar and other nutrients up
TRANSPIRATION
root -> stem -> leaf -> stoma -> atmosphere
Phloem
- living Sieve tubes
- thin walls
- with cytosol
- no organelles
- sieve plate end walls
- Companion Cells
- thin walls
- active cytoplasm
- with organelles
- connections to sieve cells
- Parenchyma (living at maturity)
- conducts water and sugars and amino acids, etc
from leaves to rest of plant (both up and down!)
TRANSLOCATION
leaf PS
V
root <- stem <- sugar -> stem -> apex
where apex = apical bud, flower, and/or fruit
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