Arborist ISA Chapter 1 Tree Biology
Exam Questions and Answers
Trees - ANS-Are large, woody plants with a single main trunk.
Tree Biology - ANS-Is the study of structure and function and the relationship between
them.
Anatomy and Morphology - ANS-The studies of the component parts of a tree.
Physiology - ANS-Is the study of the biological, physical, and chemical processes within
the components, providing the basis for function.
Meristems - ANS-New cells arise from the division of existing cells. This process
occurrs in specialized zones called what?
Primary Growth - ANS-Growth of shoots and roots from the apical meristems.
Cambium - ANS-Is a thin sheath of dividing cells that produces the cells that will
become the vascular system of the tree. This is the first lateral meristem.
Periderm - ANS-Contains protective tissues that moderate the temperature inside the
stem; defend against injury; reduce water loss. Also called the bark of the tree.
Sapwood - ANS-xylem that conducts water
Heartwood - ANS-nonconducting tissue that contains no living cells and is sometimes
darker in color than the sapwood, this tissue is locate farther inside the tree.
Phloem - ANS-moves carbohydrates (sugars) produced in the leaves throughout the
plant for storage and consumption.
Sieve Cells - ANS-phloem in conifers
Sieve tube elements and companion cells - ANS-phloem in hardwoods
Rays - ANS-are made up of parenchyma cells that grow radially across the grain in
small layers that extend across the growth increments of xylem and into the phloem.
, Bark - ANS-is the outer covering of a tree's branches, stems, and, in some cases, roots.
It is composed of protective tissues that moderate the temperature inside the stem, offer
defense against injury, and reduce water loss.
Lenticels - ANS-small openings in the bark that permit gas exchange.
Twigs - ANS-are small stems that provide support structure for leaves, flowers, and
fruits
Buds - ANS-can occur along the twig, at the base of each leaf just under the bark, or at
the tip of each twig
Apical or terminal buds - ANS-buds located at the end of a shoot.
Lateral or axillary buds - ANS-buds that occur along the stem
Adventitious buds - ANS-are produced along the stems or roots where primary
meristems are not normally found
Epicormic - ANS-dormant buds that elongate and produce shoots
Node - ANS-is a slightly enlarged portion of the twig where leaves and buds arise
Internode - ANS-is the area between nodes
Branch Collar - ANS-a shoulder or a bulge around the branch base which is a result of
the annual production of layers of tissue at the junction of the branch to the stem.
Branch bark Ridge - ANS-bark which is pushed up as a result of the branch and trunk
expanding against each other
Included bark - ANS-bark in crotch that is surrounded by wood. It further weakends the
crotch because the normal branch to trunk attachment is not formed
Leaves - ANS-are the food producers of the tree which contain chloroplast
Chloroplasts - ANS-contain a green pigment called chlorophyll
Chlorophyll - ANS-is the primary leaf pigment that absorbs sunlight
Transpiration - ANS-is the loss of water through the foliage in the form of water vapor,
which helps cool the leaf and draw water up through the xylem
Cuticle - ANS-a waxy layer covering the outer surface of a leaf
Exam Questions and Answers
Trees - ANS-Are large, woody plants with a single main trunk.
Tree Biology - ANS-Is the study of structure and function and the relationship between
them.
Anatomy and Morphology - ANS-The studies of the component parts of a tree.
Physiology - ANS-Is the study of the biological, physical, and chemical processes within
the components, providing the basis for function.
Meristems - ANS-New cells arise from the division of existing cells. This process
occurrs in specialized zones called what?
Primary Growth - ANS-Growth of shoots and roots from the apical meristems.
Cambium - ANS-Is a thin sheath of dividing cells that produces the cells that will
become the vascular system of the tree. This is the first lateral meristem.
Periderm - ANS-Contains protective tissues that moderate the temperature inside the
stem; defend against injury; reduce water loss. Also called the bark of the tree.
Sapwood - ANS-xylem that conducts water
Heartwood - ANS-nonconducting tissue that contains no living cells and is sometimes
darker in color than the sapwood, this tissue is locate farther inside the tree.
Phloem - ANS-moves carbohydrates (sugars) produced in the leaves throughout the
plant for storage and consumption.
Sieve Cells - ANS-phloem in conifers
Sieve tube elements and companion cells - ANS-phloem in hardwoods
Rays - ANS-are made up of parenchyma cells that grow radially across the grain in
small layers that extend across the growth increments of xylem and into the phloem.
, Bark - ANS-is the outer covering of a tree's branches, stems, and, in some cases, roots.
It is composed of protective tissues that moderate the temperature inside the stem, offer
defense against injury, and reduce water loss.
Lenticels - ANS-small openings in the bark that permit gas exchange.
Twigs - ANS-are small stems that provide support structure for leaves, flowers, and
fruits
Buds - ANS-can occur along the twig, at the base of each leaf just under the bark, or at
the tip of each twig
Apical or terminal buds - ANS-buds located at the end of a shoot.
Lateral or axillary buds - ANS-buds that occur along the stem
Adventitious buds - ANS-are produced along the stems or roots where primary
meristems are not normally found
Epicormic - ANS-dormant buds that elongate and produce shoots
Node - ANS-is a slightly enlarged portion of the twig where leaves and buds arise
Internode - ANS-is the area between nodes
Branch Collar - ANS-a shoulder or a bulge around the branch base which is a result of
the annual production of layers of tissue at the junction of the branch to the stem.
Branch bark Ridge - ANS-bark which is pushed up as a result of the branch and trunk
expanding against each other
Included bark - ANS-bark in crotch that is surrounded by wood. It further weakends the
crotch because the normal branch to trunk attachment is not formed
Leaves - ANS-are the food producers of the tree which contain chloroplast
Chloroplasts - ANS-contain a green pigment called chlorophyll
Chlorophyll - ANS-is the primary leaf pigment that absorbs sunlight
Transpiration - ANS-is the loss of water through the foliage in the form of water vapor,
which helps cool the leaf and draw water up through the xylem
Cuticle - ANS-a waxy layer covering the outer surface of a leaf
