ISA Arborist Test Questions and Answers Graded A+
Meristems - Answers specialized zones where new cells arise from the division of existing cells
Differentiation - Answers changes cell structure and permits them to assume a variety of specific
functions
Primary Meristem - Answers produce cells that result in elongation of shoots and roots
Secondary meristems (lateral meristems) - Answers produce cells that result in increase in diameter
Cambium - Answers The first lateral meristem
Thin sheath of dividing cells that produces the cells that will become the vascular system of the tree
Cork Cambium - Answers second lateral meristem, produces the bark
Xylem - Answers "wood of the tree" produced by the cambium is responsible for the following:
coeducation of water and dissolved minerals, support of the weight of the tree, storage of carb reserves,
defense against the spread of disease and decay
Vessels - Answers the primary conducting elements in hardwoods, hollow cells that form long tubes of
water-conducting elements
ring porous trees - Answers form wide vessels early in the growing season and narrower vessels later in
the season
include: elms (Ulmus) Oaks (Quercus) and ashes (Fraxinus)
Difuse porous trees - Answers produce vessels of uniform size throughout the growing season
include: maples (Acer) planetrees (Platanus) and poplars (Populus)
Sapwood - Answers xylem that conducts H20
Heartwood - Answers nonconductiong tissue that is sometimes darker in color than the sapwood
Phloem - Answers composed of living cells - responsible for the movement of sugars produced in the
leaves to other plant parts
sieve cells - Answers phloem cells in conifers
sieve tube elememts/companion cells - Answers phloem cells in hardwoods
axial transport system - Answers transports materials longitudinally
, Rays - Answers transport sugars and other compounds through the trunk, store starch, and assist in
restricting decay in wood tissue
Bark - Answers moderates the temperature inside the stem, defends against injury, and reduces water
loss. Outer bark is composed of nonfunctional phloem and corky tissue
Lenticels - Answers small openings in the bark the permit gas exchange
terminal/apical buds - Answers bud located at the end of a shoot - most active
axillary/lateral buds - Answers buds that occur along the stem - usually dormant
epicormic - Answers when dormant buds elongate and produce shoots
node - Answers slightly enlarged portion of the twig where the leaves and buds arise
Branch collar - Answers the annual production of layers of tissue at the junction of the branch to the
stem forming a shoulder or bulge around the branch base
Branch bark ridge - Answers formed by bark pushing up
included bark - Answers bark in crotch that is surrounded by wood
Transpiration - Answers the loss of h20 through the foliage in the form of water vapor, which helps cool
the leaf and draw water up through the xylem
cuticle - Answers the waxy layer the covers the outer surface of the leaf, helps prevent uncontrolled
water loss from the epidermal cells on the leaf surface
guard cells - Answers regulate the opening and closing of the stomata in response to environmental
stimuli such as light, temperature, and humidity
Abscission zone - Answers enables leaf drop in the fall and protects the region of the stem from which
the leaf has fallen against desiccation and pathogen entry
Functions of tree roots - Answers anchorage, storage, absorption, and conduction
Absorbing roots - Answers small, fibrous, primary tissues that grow at the ends of the main, woody
roots. Found in the upper 12in of soil
meristematic zone - Answers located at the root tip and is where the cells divide and grow in length
lateral/horizontal roots - Answers located near the soil surface
sinker roots - Answers grow vertically downward off the lateral roots and provide anchorage and
increases the depth of soil exploited by the root system
Photosynthesis - Answers needs water and carbon dioxide
Meristems - Answers specialized zones where new cells arise from the division of existing cells
Differentiation - Answers changes cell structure and permits them to assume a variety of specific
functions
Primary Meristem - Answers produce cells that result in elongation of shoots and roots
Secondary meristems (lateral meristems) - Answers produce cells that result in increase in diameter
Cambium - Answers The first lateral meristem
Thin sheath of dividing cells that produces the cells that will become the vascular system of the tree
Cork Cambium - Answers second lateral meristem, produces the bark
Xylem - Answers "wood of the tree" produced by the cambium is responsible for the following:
coeducation of water and dissolved minerals, support of the weight of the tree, storage of carb reserves,
defense against the spread of disease and decay
Vessels - Answers the primary conducting elements in hardwoods, hollow cells that form long tubes of
water-conducting elements
ring porous trees - Answers form wide vessels early in the growing season and narrower vessels later in
the season
include: elms (Ulmus) Oaks (Quercus) and ashes (Fraxinus)
Difuse porous trees - Answers produce vessels of uniform size throughout the growing season
include: maples (Acer) planetrees (Platanus) and poplars (Populus)
Sapwood - Answers xylem that conducts H20
Heartwood - Answers nonconductiong tissue that is sometimes darker in color than the sapwood
Phloem - Answers composed of living cells - responsible for the movement of sugars produced in the
leaves to other plant parts
sieve cells - Answers phloem cells in conifers
sieve tube elememts/companion cells - Answers phloem cells in hardwoods
axial transport system - Answers transports materials longitudinally
, Rays - Answers transport sugars and other compounds through the trunk, store starch, and assist in
restricting decay in wood tissue
Bark - Answers moderates the temperature inside the stem, defends against injury, and reduces water
loss. Outer bark is composed of nonfunctional phloem and corky tissue
Lenticels - Answers small openings in the bark the permit gas exchange
terminal/apical buds - Answers bud located at the end of a shoot - most active
axillary/lateral buds - Answers buds that occur along the stem - usually dormant
epicormic - Answers when dormant buds elongate and produce shoots
node - Answers slightly enlarged portion of the twig where the leaves and buds arise
Branch collar - Answers the annual production of layers of tissue at the junction of the branch to the
stem forming a shoulder or bulge around the branch base
Branch bark ridge - Answers formed by bark pushing up
included bark - Answers bark in crotch that is surrounded by wood
Transpiration - Answers the loss of h20 through the foliage in the form of water vapor, which helps cool
the leaf and draw water up through the xylem
cuticle - Answers the waxy layer the covers the outer surface of the leaf, helps prevent uncontrolled
water loss from the epidermal cells on the leaf surface
guard cells - Answers regulate the opening and closing of the stomata in response to environmental
stimuli such as light, temperature, and humidity
Abscission zone - Answers enables leaf drop in the fall and protects the region of the stem from which
the leaf has fallen against desiccation and pathogen entry
Functions of tree roots - Answers anchorage, storage, absorption, and conduction
Absorbing roots - Answers small, fibrous, primary tissues that grow at the ends of the main, woody
roots. Found in the upper 12in of soil
meristematic zone - Answers located at the root tip and is where the cells divide and grow in length
lateral/horizontal roots - Answers located near the soil surface
sinker roots - Answers grow vertically downward off the lateral roots and provide anchorage and
increases the depth of soil exploited by the root system
Photosynthesis - Answers needs water and carbon dioxide
