ISA ARBORIST CERTIFICATION EXAM
WITH 100% VERIFIED SOLUTIONS
2024/2025 |RATED A+
Meristem
Specialized zones where the process of cell division takes place. Primary and
Secondary
Differen<a<on
Change in cell structure to assume a variety of roles
Tree Organs
Leaves, stems, roots, flowers, fruit
Primary meristems
Where primary growth occurs. Growth of shoots and roots from apical
meristems
Primary Growth
Growth of shoots and roots from apical meristems
Secondary meristems
Tissue associated with diameter growth in stems, branches, roots, and
producing wood--> secondary growth. Palms lack secondary growth
Apical meristem
Meristems located at the ends of shoots and roots. In shoots they are found
inside buds
Buds
Where apical meristem is found in shoots. Meristema<c <ssue is protected by
overlapping scales
Cambium
,Secondary or lateral meristem. Thin sheath of dividing cells that produces th
cells that will become the vascular system of the tree. Produces xylem and
phloem
Cork cambium
Second lateral meristem aNer cambium. This produces the bark or periderm
Periderm
Bark
Cellulose
Structural component of primary cell wall. Most common organic compound
on Earth.
Lignin
Component of plant cells with cellulose. When formed in the cell walls of the
wood, it provides the strength and rigidity
Xylem
Wood of tree. Composed of both living and dead elements: symplasm and
apoplasm
Xylem func<ons
4.
1. Conduc<on of water and dissolved minerals
2. Support of the weight of the tree
3. Storage of carbohydrate reserves
4. Defense against the spread of disease and decay
Symplasm
Living <ssue of the tree
Apoplasm
Nonliving <ssue of the tree
Xylem of Gymnosperms
,(pines and spruces) Composed of
1. Tracheids
2. Fibers
3. Parenchymal cells
Tracheids
Conduct water and provide mechanical support. Part of the xylem. Elongated
dead cells with pointy ends and thickened walls. Less efficient than vessels for
water conduc<on
Fibers
Part of xylem. Provide mechanical strength
Parenchymal cells
-living cells interspersed among the other xylem cells. Those located in the
outer layers of the xylem store carbs, help defend agaisnt decay, and have a
structural func<on across the grain.
-Are more abundant in hardwood trees and are arranged close to the vessel
elements
Xylem of Hardwoods
1. Tracheids
2. Fibers
3. Parenchymal cells
4. Vessels
Vessels
Primary conduc<ng elements of hardwoods. Stacks of dead, hollow cells that
from long tubes of water-conduc<ng elements. Much more efficient in water
conduc<on than are tracheids.
Ring porous
, Characteris<c of trees where they form wide vessels early in the growing
season and narrower vessels later: Ulmus,quercus, fraxinus and others.
Ring Porous Species
Ulmus, Quercus, Fraxinus
Diffuse Porous
Characteris<c where the tree produces vessels of uniform size throughout
growing season. Species include: Acer, Platanus, and Populus, and others.
Diffuse porous species
Acer, Platanus, Populus
Growth rings
Visible in xylem when tree viewed in cross sec<on. The result of seasonal
produc<on of xylem by the cambium. Appear as rings because the rela<ve size
and density of the vascular <ssues change throughout the growing season. As
season goes on, cells become smaller.
Nonporous Wood
What conifers ar conisdered as opposed to diffuse or ring porous given their
lack of vessels.
Sapwood
Xylem that conducts water. Contains many living parenchymal cells.
Heartwood
Older xylem near the center of a woody stem that no longer conducts water
Phloem
-Living vascular <ssue that carries sugar and organic substances throughout a
plant.
-Moves carbs produced in the leaves throughout the plant for storage or
consump<on. Movement is rela<vely slow and occurs along a pressure
gradient--> requires energy
WITH 100% VERIFIED SOLUTIONS
2024/2025 |RATED A+
Meristem
Specialized zones where the process of cell division takes place. Primary and
Secondary
Differen<a<on
Change in cell structure to assume a variety of roles
Tree Organs
Leaves, stems, roots, flowers, fruit
Primary meristems
Where primary growth occurs. Growth of shoots and roots from apical
meristems
Primary Growth
Growth of shoots and roots from apical meristems
Secondary meristems
Tissue associated with diameter growth in stems, branches, roots, and
producing wood--> secondary growth. Palms lack secondary growth
Apical meristem
Meristems located at the ends of shoots and roots. In shoots they are found
inside buds
Buds
Where apical meristem is found in shoots. Meristema<c <ssue is protected by
overlapping scales
Cambium
,Secondary or lateral meristem. Thin sheath of dividing cells that produces th
cells that will become the vascular system of the tree. Produces xylem and
phloem
Cork cambium
Second lateral meristem aNer cambium. This produces the bark or periderm
Periderm
Bark
Cellulose
Structural component of primary cell wall. Most common organic compound
on Earth.
Lignin
Component of plant cells with cellulose. When formed in the cell walls of the
wood, it provides the strength and rigidity
Xylem
Wood of tree. Composed of both living and dead elements: symplasm and
apoplasm
Xylem func<ons
4.
1. Conduc<on of water and dissolved minerals
2. Support of the weight of the tree
3. Storage of carbohydrate reserves
4. Defense against the spread of disease and decay
Symplasm
Living <ssue of the tree
Apoplasm
Nonliving <ssue of the tree
Xylem of Gymnosperms
,(pines and spruces) Composed of
1. Tracheids
2. Fibers
3. Parenchymal cells
Tracheids
Conduct water and provide mechanical support. Part of the xylem. Elongated
dead cells with pointy ends and thickened walls. Less efficient than vessels for
water conduc<on
Fibers
Part of xylem. Provide mechanical strength
Parenchymal cells
-living cells interspersed among the other xylem cells. Those located in the
outer layers of the xylem store carbs, help defend agaisnt decay, and have a
structural func<on across the grain.
-Are more abundant in hardwood trees and are arranged close to the vessel
elements
Xylem of Hardwoods
1. Tracheids
2. Fibers
3. Parenchymal cells
4. Vessels
Vessels
Primary conduc<ng elements of hardwoods. Stacks of dead, hollow cells that
from long tubes of water-conduc<ng elements. Much more efficient in water
conduc<on than are tracheids.
Ring porous
, Characteris<c of trees where they form wide vessels early in the growing
season and narrower vessels later: Ulmus,quercus, fraxinus and others.
Ring Porous Species
Ulmus, Quercus, Fraxinus
Diffuse Porous
Characteris<c where the tree produces vessels of uniform size throughout
growing season. Species include: Acer, Platanus, and Populus, and others.
Diffuse porous species
Acer, Platanus, Populus
Growth rings
Visible in xylem when tree viewed in cross sec<on. The result of seasonal
produc<on of xylem by the cambium. Appear as rings because the rela<ve size
and density of the vascular <ssues change throughout the growing season. As
season goes on, cells become smaller.
Nonporous Wood
What conifers ar conisdered as opposed to diffuse or ring porous given their
lack of vessels.
Sapwood
Xylem that conducts water. Contains many living parenchymal cells.
Heartwood
Older xylem near the center of a woody stem that no longer conducts water
Phloem
-Living vascular <ssue that carries sugar and organic substances throughout a
plant.
-Moves carbs produced in the leaves throughout the plant for storage or
consump<on. Movement is rela<vely slow and occurs along a pressure
gradient--> requires energy
