ISA Arborist Exam
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,3-strand Rope
rope construction in which three strands are twisted together in a spiral pattern.
7-strand, common grade cable
steel-cable construction in which seven strands are twisted together in a spiral pattern.
Used to add supplemental structural support to trees. Terminated by wrapping onto itself.
12-strand rope
for arborist ropes, a braided rope consisting of 12 strands. Most are coreless. There
are two types of 12-strand construction: a tight braid that is not easily spliceable, used
for
climbing and rigging lines; and a loose, easily spliceable braid, commonly used for slings.
,16-strand rope
for arborist ropes, a braided rope that has a 16-strand, load-bearing cover and a filler
core that is not significant in load bearing.
24-strand rope
for arborist ropes, a braided rope that has a 24-strand cover and is available in
double-braid or kernmantle construction.
abiotic disorder
plant malady caused by nonliving, environmental, or man-made agents.
abscission zone
area at the base of the petiole where cellular breakdown leads to leaf and fruit drop.
absorbing roots
fine, fibrous roots that take up water and minerals. Most absorbing roots are within the
top 12 inches (30 centimeters) of soil.
, access line
(1) second climbing line hung in a tree in case it is needed to reach a victim in an
emergency; (2) climbing line installed in a tree to gain access to, but not used to work in,
the tree.
access route
defined entrance and exit route for a property during construction, tree work, or
landscape operations.
acclimation
physiological adaptation process of plants and other living organisms to a climate or
environment different from their native environment or where originally grown.
actinomycetes
group of soil bacteria resembling fungi. Actinomycetes play a role in the decomposition
of organic matter and the release of mineral elements.
action threshold
pest population or plant damage level that requires action to prevent irreversible or
unacceptable physiological and/or aesthetic harm.
Questions Verified and
Provided with A+
Graded Answers| Latest
Updated 2026
,3-strand Rope
rope construction in which three strands are twisted together in a spiral pattern.
7-strand, common grade cable
steel-cable construction in which seven strands are twisted together in a spiral pattern.
Used to add supplemental structural support to trees. Terminated by wrapping onto itself.
12-strand rope
for arborist ropes, a braided rope consisting of 12 strands. Most are coreless. There
are two types of 12-strand construction: a tight braid that is not easily spliceable, used
for
climbing and rigging lines; and a loose, easily spliceable braid, commonly used for slings.
,16-strand rope
for arborist ropes, a braided rope that has a 16-strand, load-bearing cover and a filler
core that is not significant in load bearing.
24-strand rope
for arborist ropes, a braided rope that has a 24-strand cover and is available in
double-braid or kernmantle construction.
abiotic disorder
plant malady caused by nonliving, environmental, or man-made agents.
abscission zone
area at the base of the petiole where cellular breakdown leads to leaf and fruit drop.
absorbing roots
fine, fibrous roots that take up water and minerals. Most absorbing roots are within the
top 12 inches (30 centimeters) of soil.
, access line
(1) second climbing line hung in a tree in case it is needed to reach a victim in an
emergency; (2) climbing line installed in a tree to gain access to, but not used to work in,
the tree.
access route
defined entrance and exit route for a property during construction, tree work, or
landscape operations.
acclimation
physiological adaptation process of plants and other living organisms to a climate or
environment different from their native environment or where originally grown.
actinomycetes
group of soil bacteria resembling fungi. Actinomycetes play a role in the decomposition
of organic matter and the release of mineral elements.
action threshold
pest population or plant damage level that requires action to prevent irreversible or
unacceptable physiological and/or aesthetic harm.
