organisation: plants Flashcards
what is the function of the epidermal tissue
cover the leaf
what is the function of the palisade tissue
absorb light for photosynthesis
how id the palisade tissue adapted for its function
close towards the upper surface of the leaf, they are packed with chlorolasts and arranged closely together
what is the function os the spongy mesophyll
gas exchange
how is the spongy mesophyll adapted for its function
cells packed loosely to allow gaps between cells and cells are covered by a thing layer of water which gases dissolve in
what is the function of the xylem
transport water and dissolved mineral around the plant
how is the xylem adapted for its function
they are a dead hollow tube strengthened by lignin
what us the function of the phloem
transport sugars around the plant
how is the phloem adapted for its function
the cells do not contain a nucleus and it is supported by companion cells. the end of each cell had a siege plate to allow free movement of substances from cell to cell
what is the functions of meristems
plant stem celles that differentiate into specialised cells throughout the life of a plant
where are the meristems found in the plant
shoots and roots
what are the stomata
small pores on the underside of the lead that allow gases such as oxygen, carbon dioxide and water vapour to diffuse through
what is the function of the guard cells
open and close the stomata ti control water loss
what is the function of the roots
anchorage and absorbtion of the water and mineral ions
how are the root hair cells adapted for their function
large surface area, thin surface membrane for a short diffusion pathway and lots of mitochondria
what is absorbed by osmosis by the roots
water
what is absorbed by active transport by the roots
mindral ions
what is transpiration
the transport of water through the xylem from the roots to the leaf. it does not require energy
what is translocation
the transport of sugar through thr phloem both upwards and downwards. requires energy
what happens to the rate of transpiration if the temperature is increased and why
it increases because theres is increased evaporation from the cell surfaces and the rate of diffusion of water molecules from the lead are increased
what happens to the rate of transpiration if humity decreases and why
it decreases. the increased humidity decreases the concentration gradient between water in the leaf and water in the air so rate of diffusion of the water from the leaf decreases
what happens to the rate of transpiration if the air movement increases and why
it increases the air flow removes water vapour from leaf surfaces and so more water diffuses from the leaf
what happens to the rate of transpiration if light intensity increase and why
it increases, the light intensity increase the rate of photosynthesis so the stomata open so there js increased diffusion of water out the leaf
