Plant cell structures and functions Flashcards
(26 cards)
What is the function of the waxy cuticle?
It is a protective layer on top of the leaf, and it prevents water from evaporating.
What is the upper epidermis?
A thin and transparent layer under the cuticle.
What is the function of the upper epidermis?
It is thin to let light through to the layer underneath, the palisade mesophyll.
Name 3 adaptations of the Xylem
The walls contain lignin spirals, which keep it rigid.
It has no barriers between cells, so it is one tube to allow water to flow through easily.
The walls are impermeable, which means water can’t be absorbed.
- hollow tubes of dead xylem cells
What does the phloem transport?
dissolved sugars produced by photosynthesis from the leaves to the rest of the plant . (food for the plant)
where is meristem tissue found in a plant?
at the growing tips of shoots and roots
what does meristem tissue contain?
stem cells
what forms a plant organ system? (three main parts of the plant)
roots, stem, leaves
what are root hair cells adapted for?
To uptake water by osmosis, and mineral ions using active transport.
what is the layer of epidermal cells at the top of the leaf called?
upper epidermis
what are the very thin cells called that cover the top of the bottom of the leaf?
epidermal cells
what does the upper epidermis being transparent allow?
light to pass through to the photosynthetic cells below
What is one function of the waxy cuticle?
It prevents the leaf drying out as it reduces evaporation, and it can protect from pathogens.
What is the function of the lower epidermis?
it allows carbon dioxide to enter the leaf and oxygen to leave.
where is the palisade mesophyll located?
At the top of the leaf, just below the upper epidermis.
what do palisade cells contain? (hint - where photosynthesis happens)
Chloroplasts
where is the spongy mesophyll located?
in the middle of the leaf, below the palisade mesophyll and above the lower epidermis
What is one adaptation of the spongy mesophyll?
It has air spaces, which allow carbon dioxide to diffuse from the stomata to the palisade cells
and oxygen to diffuse from the palisade cells to the stomata
what do the end of phloem cells contain?
sieve plates which are full of holes to allow specific molecules to move up and down the phloem vessel throughout the plant
what are stomata?
small holes on the underside of a leaf that allow the diffusion of gases in and out of the cell
what are guard cells?
cells that surround the stomata and open and close it
How do guard cells open and close the stomata?
They take in water which causes them to swell (open), or they let out water which makes them shrink (close)
what gas do the stomata allow in to the cell?
carbon dioxide in, oxygen out.
Why does a plant need carbon dioxide?
For photosynthesis.
