| A | B |
|---|
| root system | found generally underground & obtains water and dissolved nutrient minerals for the plant |
| shoot system | generally aerial & obtains sunlight and exchanges gases, such as carbon dioxide & oxygen |
| ground tissue system | consists of the parenchyma, collenchyma, & sclerenchyma |
| parenchyma | composed of living cells with thin primary cell walls. Functions in photosynthesis, storage, & secretion |
| collenchyma | has unevenly thick cell walls. Provides flexible structural support |
| sclerenchyma | has both primary & secondary cell walls; often dead at maturity, but provide structural support |
| schlereids | function in hard, inflexible tissue; cherry & peach pits, walnut & coconut shells |
| tracheids | xylem, dead at maturity |
| vessel elements | xylem; dead at maturity; have end wall perforations |
| sieve tubes | phloem; living, but lack nucleus & other organells at maturity; conducts sugar solution |
| companion cell | phloem; living; assists in the moving sugars |
| dermal tissue | outer protective covering of the plant body |
| epidermis | outer layer of cells; functions in protection |
| periderm | forms the outer bark of oler stems & roots; replaces epidermis as woody plant increase in girth |
| meristem | localized area where growth occurs |
| primary growth | an increase in stem or root length |
| apical meristems | primary growth regions in the tips of the roots & buds of the stems |
| secondary growth | increase in stem & root girth (thickness) |
| lateral meristem | areas in which secondary growth occurs |
| vascular cambium | layer of meristematic cells that forms long, thin cylinder within the stem & root trunk |
| cork cambium | composed of a thin cylinder or irregular arrangement of meristematic cells; located in the outer bark |
