plants as organisms (ch9) Flashcards
whats meanbt by translocation
when the phloem moves dissolved sugars from the leaves to the rest iof the plant (including storage organs and growing areas)
whats the transpiration stream
the movement if water through the xylem and out of the leaves
how does carbon dioxide enter leaves
by diffusion through the stomata
how do water and mineral ions enter plants
absorbed by roots through the xylem to stem and leaves
where does most loss of water evaporation take place
stomata
which cell controls the size of the stomata
guard cells
when is evaporation more rapid
in hot dry and windy conditions
whatre the measures plants take if water loss is faster than its replaced
plant either wilts (droops leaves) or stomata closes
whatre the 3 functions of the stomata
-obtain carbon dioxide from the atmosphere
-remove oxygen from photosynthesis
-control rate of water loss
how are plants adapted to theur functions
-broad leaves for larger SA
-leaves contain phloroplast to absorb sunlight
-air spaces for co2 in and o2 out by diffusion
-veins bring in water by xylem which is removed by phloem
what 3 factors limit photosynthesis
- temperature
-light
-carbon dioxide levels
why do farmers use greenhouses
to control conditions and increase light intensity,co2 concentration and temperatures to maximise photosynthesis which maximises yields and profit
whatre the 5 ways plants use starch (SCARF)
-starch for storage
- cellulose to strengthen their cell wall
- amino acids (combine glucos w nitrate ions)
-respiration
- fats and oils (for storing energy)
whats the function of phloem
to carry dissolved sugars from leaves to the rest of the plant (translocation)
whats the function of xylem
to transport water and ions from the roots to the stem and leaves
