Plant Tissues,Organs and Organ Systems Flashcards
what is the epidermis?
The outermost layer of cells of a plant
What are the functions of the epidermis?
protecting against water loss
regulating the gases that are exchanged between the plant and air
water and mineral uptake
why is the epidermis transparent?
light can pass through it and reach the palisade mesophyll
what is the palisade mesophyll?
tissue found towards the upper surface of leaves with lots of chloroplasts for photosynthesis
what is the spongy mesophyll?
tissue found towards the bottom surface of the leaves with spaces between them to allow gases to diffuse
why do spongy mesophylls have a large surface area?
to maximise gas exchange
why do pores in stomata become smaller?
to reduce the amount of water being lost in transpiration
explain the practical : observing stomata on leaves…
select the plant you want to study and use a small paintbrush to coat a small section of the upper and lower epidermis of a leaf with a water based nail varnish
leave it to dry
use the tweezers and sticky tape to remove the varnish impressions from the leaves and mount onto a labelled slide
observe the stomata using a microscope
draw and sketch
What is the meristem?
a region of plant tissue in which the stem cells are produced and so where much of the plants growth occurs
What are the three plant organs?
Root
Leaf
Shoot
Why are plant roots white?
they are found under the soil
as a result they are white because they don’t contain chloroplast
where is the meristem found?
at the very tip of the shoot
What is the function of the leaf?
major site of photosynthesis
controls the flow of water through the plant
What are the functions of Transpiration?
providing water for leaf cells and other cells
providing water to cells for the process of photosynthesis
transporting minerals to the leaves
How are high rates of transpiration achieved?
more wind
high temperatures
less humid
high light intensity
