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

What are stomata?

1. Cell membranes of chloroplasts

2. Small openings on the underside of a leaf

3. Energy-producing organelles

4. Parts of a nucleotide

The correct answer is: Small openings on the underside of a leaf

Stomata are small openings located primarily on the underside of a leaf. They serve as gateways for gas exchange, allowing carbon dioxide to enter the leaf for photosynthesis and enabling the release of oxygen as a byproduct. This exchange is essential for plant respiration and overall function. Stomata also play a critical role in regulating water loss through transpiration, which helps maintain the plant’s water balance and contributes to nutrient transport. The presence of stomata on the underside of leaves, where they are typically more sheltered from wind and direct sunlight, helps optimize the balance between gas exchange and minimizing water loss. Understanding the structure and function of stomata is vital in the study of plant biology, as they are key regulators in photosynthesis and plant health.