what is each organ in a multicellular plant made up of? | specialised cells |
why do plants need transport systems? | to transport water, minerals and glucose around the plant |
what is the cuticle of a plant | waterproof layer that reduces water loss from the leaf |
what is the upper epidermis cells of a plant? | protects leaf and allows light to pass through to the layer below |
what is the function of palisade mesophyll cells? | absorbs light for photsynthesis |
what is the function of spongy mesophyll cells? | absorbs light for photosynthesis |
what is the function of the xylem (vein) | transports water from soil to leaf for photosynthesis |
what is the function of the phloem (vein) | transports sugar from photosynthesising cells to the rest of the plant |
what is the function of air spaces in a plant? | allows the diffusion of gases within the leaf |
what is the function of stoma in a plant | allows the carbon dioxide to enter the leaf and oxygen to exit the leaf |
what is the function of guard cells in a plant? | controls gas exchange between the leaf and the air outside the leaf |
what is number one in this diagram | cuticle |
what is number two in this diagram | upper epidermis |
what is number 3 in this diagram | palisade mesophyll |
what is number 4 in this diagram | spongy mesophyll |
what is number 5 in this diagram | lower epidermis |
what is number 6 in this diagram | stoma |
what is number 7 in this diagram | guard cell |
what is number 8 in this diagram | xylem |
what is number 9? | phloem |
what is number 10 | vascular bundle |
what are plant organs | roots
stems
leaves |
what part of the plant is involved in water transport | xylem vessel |
describe water transport through the xylem vessel from the root of a plant | water and minerals enter the plant through the root hairs and are transported in the dead xylem vessels |
why are xylem vessels lignified? | xylem vessels are lignified to withstand pressure changes as water moves through the plant |
what is transpiration | the process of moving water through the plant and its evaporation through the stomata |
what is the rate of transpiration affected by? | wind speed, humidity, temperature and surface area |
how is sugar transported in a plant | sugar is transported up and down the plant in living phloem |
what features do phloem cells have? | sieve plates and associated companion cells |
what apparatus is used to measure transpiration rates | potometer |
why is it necessary to have a layer of oil on the surface of the water in a potometer | to prevent evaporation of water from the surface of water in the beaker |
how are root hair cells specialised | they have a large surface area to abosrb water from the surrounding soil. |
how does water enter the root hair cells of a plant | there is a water concentration graident between the soil and the xylem vessel inside the root. water enters the root hair cells through the process called osmosis and travels from cell to cell. |
how is water moved from the plant to the leaf | mesophyll cells in the plant leaf have a lower water concentration than the xylem
water moves by osmosis from a high water concentration in the xylem to a lower water concentration in the mesophyll cells. this water is available for photosynthesis. |
what happens to msot of the water in plant leaves | most water evaporates from leaves into the air spaces where water vapour then diffuses out through the stomata to the surrounding atmosphere |
what controls rate of transpiration | stomata |
when do stomata open and close | open in the light and close in the dark |
why would it benefit the plant if the stomata closed at night when the plant was not photosynthesising? | to avoid loss of water vapour from the plant |