Free ISA Tree Biology and Physiology Questions and Answers — Questions and Answers
Question 1: Which of the following accurately describes the primary function of phloem tissue in a tree?
- Transporting water and minerals from the roots to the leaves.
- Providing structural support to the trunk and branches.
- Transporting sugars produced during photosynthesis from the leaves to other parts of the tree. (Correct answer)
- Forming a protective outer layer against pests and diseases.
Correct answer: Transporting sugars produced during photosynthesis from the leaves to other parts of the tree.
The phloem is a critical component of a tree's vascular system responsible for transporting the sugars (produced via photosynthesis in the leaves) to areas of growth and storage, such as the roots, fruits, and meristems. Xylem transports water, heartwood provides support, and the bark is the protective layer.
Question 2: An arborist observes a tree with a tall, dominant central leader and suppressed lateral branch growth. This growth pattern is a classic example of:
- Hydraulic lift
- Apical dominance (Correct answer)
- Negative phototropism
- Compartmentalization
Correct answer: Apical dominance
Apical dominance is the phenomenon where the central, terminal bud (apical bud) produces hormones, primarily auxin, that inhibit the growth of the lateral buds below it. This results in the tree prioritizing vertical growth over lateral branching, leading to a strong central leader.
Question 3: The process by which a tree releases water vapor into the atmosphere through small pores (stomata) in its leaves is known as:
- Respiration
- Photosynthesis
- Translocation
- Transpiration (Correct answer)
Correct answer: Transpiration
Transpiration is the process of water movement through a tree and its evaporation from aerial parts, such as leaves. This process is vital for cooling the tree, moving water and nutrients from the roots, and enabling the uptake of carbon dioxide for photosynthesis.
Question 4: According to the CODIT model (Compartmentalization of Decay in Trees), which 'wall' is considered the strongest and is formed by the cambium after an injury occurs, separating new wood from the damaged tissue?
- Wall 1
- Wall 2
- Wall 4 (Correct answer)
- Wall 3
Correct answer: Wall 4
Wall 4, also known as the barrier zone, is the strongest of the four walls in the CODIT model. It is new wood tissue produced by the cambium after the injury, forming a protective barrier that prevents the spread of decay into the wood that grows after the wound occurs.
Question 5: A client is concerned about a large, mature oak tree in their yard after a recent period of soil compaction from construction equipment. Why is oxygen in the soil crucial for the health of the tree's root system?
- Oxygen is required for the roots to absorb water through osmosis.
- Roots release oxygen into the soil to deter harmful pathogens.
- Oxygen is necessary for the process of root respiration, which releases energy for growth and nutrient uptake. (Correct answer)
- Soil oxygen directly fuels the process of photosynthesis within the root cells.
Correct answer: Oxygen is necessary for the process of root respiration, which releases energy for growth and nutrient uptake.
Tree roots, like other living cells, must perform respiration to break down sugars and release energy for vital functions, including growth and the active uptake of mineral nutrients. This process requires oxygen. Soil compaction reduces pore space, limiting oxygen availability and impairing root health and function.
Question 6: Photosynthesis is the fundamental process that fuels a tree's growth. Which of the following are the three essential inputs required for this process to occur?
- Oxygen, water, and soil minerals
- Sunlight, carbon dioxide, and water (Correct answer)
- Nitrogen, chlorophyll, and sugar
- Carbon dioxide, oxygen, and sunlight
Correct answer: Sunlight, carbon dioxide, and water
The overall chemical equation for photosynthesis shows that trees use energy from sunlight to convert carbon dioxide from the atmosphere and water absorbed by the roots into glucose (sugar) and oxygen. The sugar provides the energy for all of the tree's metabolic processes.
Free ISA Tree Biology and Physiology Questions and Answers
Which of the following accurately describes the primary function of phloem tissue in a tree?