ISA Certified Arborist Exam Questions with 100% Correct Answers

ISA Certified Arborist Exam Questions with 100% Correct Answers guard cells - Pair of specialized cells that regulate the opening and closing of stomate due to the change in water pressure within cells. Functions of root system - Absorb and conduct water and minerals, anchor and support plant, storage of extra food and produce hormones. Tropism - Tendency of growth or variation of a plant in response to an external stimulus such as gravity or light. Geotropism - plant growth produced as a response to the force of gravity, either positive, as in the direction of gravity (roots), or negative, as in opposite the direction of gravity (shoots) Phototropism - Influence of light on the direction of plant growth. Tendency of plants to grow toward light.: excurrent - tree growth habit characterized by a central leader and pyramidal crown. decurrent - rounded or spreading growth habit of the crown of a tree