Cell diversity in plants Flashcards
Where are guard cells?
In the leaf epidermis, cells that surround the stomata.
What are palisade cells?
Closely-packed photosynthetic cells within leaves.
What are root hair cells?
Epidermal cells of young roots with thin hair like projections.
Palisade cells are long and cylindrical why is this beneficial in photosynthesis?
They are able to pack together tightly with little space between them for air to circulate.
Why do palisade cells have a large vacuole?
So that the chloroplasts are positioned nearer to the periphery of the cell, reducing the diffusion distance for carbon dioxide.
What organelle carries out the function of photosynthesis?
Chloroplasts
Why can guard cells not carry out photosynthesis despite them having chloroplasts?
They do not have the enzymes needed for the second stage of the process.
What energy is used to produce ATP in guard cells?
Light energy
The ATP actively transports _______ into the guard cells so that water enters the cell due to a change in ________ .
Potassium ions
Water potential
At the tips of the guard cells the cellulose is more flexible. What happens when water enters them?
It swells and create a gap called the stoma (Greek for mouth.)
What does the stoma do?
Allows air to enter the spaces within the layer of cells beneath the palisade cells.
What exits from the stomata when they open?
Water vapour and oxygen.
The hair-like projection of root hair cells increases the surface are for what?
For the absorption of water and mineral ions, such as nitrates, from the soil into which it projects.
Why are mineral ions actively transported into the cell?
To lower the water potential inside the cell creating a gradient to cause more water to enter the cell via diffusion.
What in the plasma membrane of a root cell actively transports the minerals in?
Carrier proteins.
