Certified Arborist Practice Exam

What is the term for yellowing between the leaf veins in plants?

1. Decay

2. Erosion

3. Chlorosis

4. Browning

The correct answer is: Chlorosis

The term for yellowing between the leaf veins in plants is chlorosis. This condition occurs when chlorophyll, the green pigment crucial for photosynthesis, breaks down or fails to be produced in sufficient quantities. Chlorosis typically manifests as a yellowing of the leaf tissue, particularly noticeable between the veins, while the veins themselves may remain green. Chlorosis can result from various factors, including nutrient deficiencies (such as nitrogen or iron), poor drainage, compacted soil, or root damage, which can impede the plant's ability to uptake essential nutrients. Recognizing chlorosis is important for diagnosing the health of a plant and determining appropriate corrective measures, such as fertilization or improving soil conditions. Understanding this condition allows arborists and horticulturists to take action to restore plant health. The other terms listed do not specifically refer to this leaf condition: decay usually relates to the decomposition of organic material, erosion refers to the removal of soil or rock by wind or water, and browning typically describes dead or dying leaf tissue that has turned brown, rather than the yellowing characteristic of chlorosis.