Plant Vascular System Flashcards
What is the primary organ of transport in plants?
Stem
What is the name of the bundle(s) that run up and down a plants stem?
Vascular bundles
What is the name of the bundle at the center of a plants stem that contains xylem, phloem, and cambium cells?
Fibrovascular bundle
Xylem
Thick-walled, hollow cells, located inside the vascular bundle (towards the center stem). Responsible for:
- carrying water and minerals up the plant
- providing structural support
Sapwood
The outer layer of xylem that is alive
Name the two types of xylem cells
Vessel cells and tracheids
Transpiration Pull
As water evaporates from the leaves of plants, a vacuum is created that pulls water up the stem.
Note: action of xylem cells
Capillary Action
The action by which a liquid rises against gravitational pull through a thin tube due to:
- the surface tension of the liquid
- intermolecular forces between the liquid and tube
Note: action of xylem cells
Root pressure
A form of osmotic pressure within the cells of a root system that causes water, in the form of sap, to rise through a plants stem to the leaves.
Note: action of xylem cells
Phloem Cells
Thin-walled cells located on the outside of the vascular bundle. Responsible for:
-transportation of nutrients down the stem
Note: include sieve tube cells and companion cells
Cambium
Actively dividing and undifferentiated cells that give rise to xylem and phloem.
Proceeding from the outside inwards, what are the different layers of the stem.
Epidermis (bark) –> Cortex –> Phloem –> Cambium –> Xylem –> Pith
Pith
Tissue located at the center of the stem responsible for:
- nutrient storage
- plant support
Root
Functions to absorb materials through root hairs and anchor the plant. Sometime provide storage for energy reserves.
Root Hairs
Projected from the root, these hairs increase surface area for water and mineral absorption. The epidermis contains root hair cells.
