AP BIOLOGY

Detailed explanation-1: -Plant stomata close in darkness and when conditions are very dry. Since plant cells need carbon dioxide for photosynthesis, carbon dioxide concentrations are another key factor.

Detailed explanation-2: -Water stress, high temperatures, and high carbon dioxide concentration causes stomata to close.

Detailed explanation-3: -Stomata are mouth-like cellular complexes at the epidermis that regulate gas transfer between plants and atmosphere. In leaves, they typically open during the day to favor CO2 diffusion when light is available for photosynthesis, and close at night to limit transpiration and save water.