ISA Arborist Certification (Actual) Exam Graded A+

response growth - ANSWER Reaction wood or additional wood grown to increase the structural strength of the trunks; note location and extent. meristem - ANSWER a region of plant tissue, found chiefly at the growing tips of roots and shoots and in the cambium, consisting of actively dividing cells forming new tissue. Apical - ANSWER at the end of the branch apical dominance - ANSWER Concentration of growth at the tip of a plant shoot, where a terminal bud partially inhibits axillary bud growth. xylem - ANSWER vascular tissue that carries water upward from the roots to every part of a plant phloem - ANSWER Living vascular tissue that carries sugar and organic substances throughout a plant cambium - ANSWER A layer of meristematic cells in a plant that produces new phloem and xylem cells. branch collar and branch bark ridge - ANSWER Root system function - ANSWER anchorage, absorption, storage, conduction tropism - ANSWER A growth response of a plant toward or away from a stimulus phototrpism - ANSWER the growth of a shoot toward or away from light (positive phototropism for toward and negative phototropism for away) Geotropism - ANSWER response to earth's gravity, as the growing of roots downward in the ground CODIT - ANSWER Compartmentalization Of Decay In Trees excurrent - ANSWER tree growth habit characterized by a central leader and pyramidal crown (contrast with decurrent) decurrent - ANSWER rounded or spreading growth habit of the crown of a tree cortex - ANSWER region outside the phloem Phelloderm - ANSWER In the stems of woody plants, a thin layer of cells located between the outer cork cells and inner cork cambium. cork cambium - ANSWER Lateral meristematic tissue that produces the outer covering of stems lenticles - ANSWER opening in bark of woody stem, allows air to enter stem to provide respiration internode - ANSWER A segment of a plant stem between the points where leaves are attached. lateral bud - ANSWER meristematic area on the side of a stem that gives rise to side branches leaf scar - ANSWER a scar on a stem where a leaf has been attached in a previous year terminal bud scale scars - ANSWER the scars left when the bud scales dropped off in the spring auxin - ANSWER a plant hormone that promotes root formation and bud growth cuticle - ANSWER A waxy covering on the surface of stems and leaves that acts as an adaptation to prevent desiccation in terrestrial plants. petiole - ANSWER the stalk of a leaf ray - ANSWER cells that cross the phloem and xylem for radial transport Eudicots - ANSWER Member of a clade consisting of the vast majority of flowering plants that have two embryonic seed leaves, or cotyledons. Monocot - ANSWER An angiosperm that has only one seed leaf. whorled leaf arrangement - ANSWER three or more leaves per node petiolule - ANSWER the stalk of a leaflet specific epithet - ANSWER The second part of a binomial, it refers to one species within a genus. Micropores - ANSWER are fine soil pores, typically a fraction of a millimeter in diameter. They are responsible for a soil's water-holding capacity. Like the fine pores in a sponge or towel, micropores hold water against the force of gravity. Much of the water held in micropores is available to plants, but some is held so tightly that plant roots cannot use it. Macropores - ANSWER are large soil pores, usually between aggregates, that are generally greater than 0.08 mm in diameter. Macropores drain freely by gravity and allow easy movement of water and air. They provide habitat for soil organisms and plant roots can grow into them. sodic - ANSWER Containing excessive amounts of sodium Rhizosphere - ANSWER The soil region close to plant roots and characterized by a high level of microbiological activity. gravitational water - ANSWER Drains out of pore spaces after a rain field capacity - ANSWER ability of a soil to hold water against the downward pull of gravity Water holding capacity - ANSWER how well soil can retain water (sand is low, clay is high) tensiometer - ANSWER instrument used to measure soil moisture Soil aggregates - ANSWER Soil particles that are closely bound together are called peds or aggregates bulk density - ANSWER mass of dry soil buffering capacity - ANSWER the ability of a substance to resist changes in pH root exudates - ANSWER organic compounds, such as amino acids, enzymes, and carbohydrates, that are secreted by plant roots into the surrounding soil Nitrogen Mineralization - ANSWER the conversion of an element from an organic state (biomass, SOM) to an inorganic state that plants can uptake. capillary water - ANSWER Water that clings in the micropores when at field capacity or lower structural soils - ANSWER Soils designed to meet compaction requirements along with allowing root growth. engineered soils suspended pavement - ANSWER pavement rests on structures rather than on soil available water - ANSWER Soil water between field capacity and the permanent wilting point