Plant tissues Flashcards
what are the top and bottom of the leaf that are covered with a layer of a very thin cells called?
epidermal cells
form epidermal tissue
top layer = upper epidermis
bottom layer = lower epidermis
what does the epidermis do
protects the surface of the leaf
what is the key adaptation of the upper epidermis
it’s transparent, allows light to pass though the photosynthetic cells below
what is the waxy cuticle
a thin layer of oily material that covers the upper epidermis
what does the waxy cuticle do
reduces evaporation of water from the surface of the leaf which prevents the leaf from drying out
what is stomata
the tiny pores in the lower epidermis
what does a stomata do
allows carbon dioxide to enter the leaf and oxygen to leave
controls the amount of water vapour that can pass out of the leaf
where do we find guard cells
on either side of the stomata
where is the palisade mesophyll
at the top of the leaf
what does the palisade mesophyll consist of?
palisade cells
what are in palicide cells
palisade cells are packed full of chloroplasts(which contain chlorophyll that absorbs the light energy needed for photosynthesis)
what is underneath the palisade mesophyll?
the spongy mesophyll
what is the key feature of the SPONGEY mesophyll
full of air spaces
what do the air spaces in the spongy mesophyll do?
the air spaces allow carbon dioxide to diffuse from the stomata through the spongey mesophyll to the palisade cells
what 2 substances diffuse through the spongey mesophyll
carbon dioxide - from the stomata and through the spongey mesophyll to the palisade cells
oxygen- from the palisade cells through the spongey mesophyll to the stomata
