2.5 Gaseous Exchange in Plants Flashcards
What process in plants requires oxygen and releases carbon dioxide?
Cell respiration.
What gas is required by plants for cell respiration?
Oxygen.
What gas is released into the air by plants during respiration?
Carbon dioxide.
What is the function of the stoma in plant leaves?
To allow gas exchange (oxygen, carbon dioxide, and water vapor).
What causes the stoma to open?
The guard cells swell with water, becoming turgid.
What causes the stoma to close?
The guard cells swell with water, becoming turgid.
What are the green structures inside the guard cells?
Chloroplasts.
What controls the shape of the guard cells?
The vacuole and water pressure inside the cell.
What do guard cells do?
Control the opening and closing of the stoma.
What happens to the stoma during the day?
It opens to allow gas exchange for photosynthesis.
Why does the stoma open during the day?
Water enters the guard cells by osmosis, making them turgid and curved.
What gases move in and out of open stomata?
Oxygen enters; carbon dioxide exits.
What happens to the stoma at night?
It closes because photosynthesis does not occur.
Why does the stoma close at night?
Water exits the guard cells by osmosis, making them flaccid and wrinkled.
How does smoke, dust, and haze affect stomata?
They clog stomata, reducing the rate of photosynthesis.
How does haze affect photosynthesis?
It blocks sunlight, reducing light energy for photosynthesis.
How do toxic gases affect plants?
They dissolve in rain, creating acid rain which lowers soil pH and harms crops.
Why do climbers use oxygen tanks at higher elevations?
The air pressure and oxygen levels are much lower.
What causes breathing difficulty at high altitudes?
Small pressure differences between the thoracic cavity and the atmosphere reduce lung air volume.
Why doesn’t a climber need an oxygen tank at 4,000 m?
The oxygen level and pressure are higher compared to 9,000 m, so breathing is manageable.
