Ohio Assessment for Educators (OAE) Integrated Science (024) Practice Exam

What is the importance of transpiration in plants?

1. It nourishes plant roots

2. It cools the plant and helps nutrient transport

3. It aids in seed dispersal

4. It promotes photosynthesis

The correct answer is: It cools the plant and helps nutrient transport

Transpiration is a vital process in plants that primarily involves the movement of water from the roots through the plant and its eventual evaporation from the surface of leaves. This process serves several essential functions, making option B the most accurate choice. One significant aspect of transpiration is its role in cooling the plant. As water evaporates from the leaf surfaces, it carries away heat, which prevents the plant from overheating. This cooling effect is crucial during hot weather or when the plant experiences high levels of sunlight. Additionally, transpiration creates a negative pressure within the plant's vascular system, specifically in the xylem. This pressure difference is what drives the upward movement of water and dissolved nutrients from the roots to the various parts of the plant. As water is lost through transpiration, more is drawn up from the soil, ensuring that nutrients are effectively transported to areas where they are needed for growth and metabolic functions. In essence, transpiration helps maintain the plant's temperature and is fundamental in the processes of nutrient uptake and distribution, making it indispensable for overall plant health and development.