gaseous exchange in plants Flashcards
(18 cards)
Where is the waxy cuticle?
Covers the leaves and allows very little gaseous exchange.
What are the main structures involved in gas exchange in the leaves?
The stomata, mesophyll cells and the air spaces between them.
What are the stomata?
The pores in the epidermis of the leaves and are surrounded by guard cells.
Where do gases diffuse in and out of the leaf?
The stomata.
What provides the leaves with a short diffusion pathway?
The leaves are thin.
What is the role of the waxy cuticle?
Reduces water loss.
What does the spongy mesophyll have between the cells?
Air space.
What does this provide?
Larger surface area, shortens diffusion distance.
How often do plants respire?
24 hours a day.
When doesn’t photosynthesis occur?
At night.
What happens more in the day - photosynthesis or respiration?
Photosynthesis.
What does this mean about gas exchange in the plant?
There is a net uptake of carbon dioxide and loss of oxygen.
What does it mean if the stoma is open?
Gas exchange is occurring.
What does it mean if the stoma is closed?
Reduces water loss.
How are plants adapted to maintain diffusion gradients?
Respiration and photosynthesis by using and producing oxygen and carbon dioxide.
How is the leaf adapted for a large surface area?
Numerous mesophyll cells lining the intercellular spaces in the leaf provide a large surface area for gaseous exchange.
What are the cells next to the stomata called?
Guard cells.
What is the pathway for gases diffusing into the plant?
Through the stoma, down a concentration gradient and through the intercellular air spaces and they dissolve into the moist cell wall of mesophyll cells.
