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Lateral Maritem
Cells responsible for the increase in girth of growing branches, trunks, and roots
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Xylem
Vascular system to the INSIDE of the cambium. Responsible for the transport of water up through the tree by osmosis (area of high potential to area of low potential)
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Phloem
Vascular system to the outside of the cambium. Transports photosynthate up and down the tree. Nutrients travel from source to sink (leaves to plant parts that use more than produce).
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Stoma (pl. Stomata)
Pores on the underside of leaves that are used for gas exchange. Regulated by guard cells. Take in CO2 for photosynthesis.
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Apical Meristem
Cells at the tip of a root or shoot responsible for increase in length.
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Lateral Meristem
Cells that are responsible for the increase in girth of growing branches, trunks and roots.
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Growth Rings
Visible difference in the xylem produced during the season. Wood formed early have large cells, later have compact cells leaving a distinct line.
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Conduction- roots transport water and nutrients to and from using osmosis
Anchorage- permeate the soil to anchor the plant
Storage- excess sugars are stored
Absorption- absorb water and minerals from soil
Four Primary Functions of Roots
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Bud Scales
Modified leaves that protect buds/above ground meristems.
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Root cap
Protect meristematic cells in root tips. As a root grows, this decomposes to provide lubrication for roots to move through the soil.
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CODIT
Compartmentalization of Decay in Trees
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CODIT Wall 1
- CODIT- Stops decay up and down
- Formed by plugging up normally porous vascular tissue above and below the wound. This tissue runs up and down the length of the stem, so plugging it slows the vertical spread of decay. This wall is the weakest.
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CODIT Wall 2
- CODIT- Stops decay from going in.
- This wall is formed by the cells of the growth ring
- interior to the wound, thus slowing the inward spread of decay. This
- wall is the second weakest.
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CODIT Wall 3
- CODIT- Stops decay laterally.
- The third wall is formed by ray cells, which are groups of cells
- oriented perpendicularly to the stem axis, dividing the stem into
- sections not entirely unlike the slices of a pie. These groups of cells
- are not continuous and vary in length, height and thickness, forming a maze-like
- barrier to lateral growth of decay. After wounding, some ray cells are
- also altered chemically, becoming poisonous to some microorganisms. This
- is the strongest wall at the time of wounding.
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CODIT Wall 4
- CODIT- New xylem forms over the wound, called barrier zone.
- Created by new growth on the exterior of the tree, isolating tissue
- present at the time of infection from that which will grow after. This
- is the strongest wall, and often the only one which will completely halt
- the spread of infection.
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