transport systems in living things Flashcards
definition of diffusion
Movement of particles from a region of higher
concentration to a region of lower concentration (until equilibrium is reached).
definition of osmosis
Net movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane
(semi-permeable/ selectively permeable)
how does a unicellular organism transport essential substances
- nutrients → undergo gaseous exchange by diffusion
- water → osmosis
Why can’t a multicellular organism obtain its nutrients by diffusion and its water by osmosis alone?
oxygen would take a relatively longer time to reach all the cells of a multicellular organism which is not suitable for survival
what does the xylem do
transport water and mineral ions from the roots to the rest of the plant
what does the phloem do
transport sugars and amino acids from the leaves to the rest of the plant
where is the phloem located
outside
where is the xylem located
inside
what is a stomata
small openings in the leaves through which diffusion can take place
what is the gaseous exchange that happens
- oxygen from inside the leaf → outside
- carbon dioxide from ouside the leaf → inside
how does the oxygen go out of the leaf
gaseous exchange
diffusion
why does the oxygen diffuse from inside the leaf to outside
oxygen diffuses from inside the leaf where there is a higher concentration → outside the leaf where there is a lower concentration
what is the process of the minerals being transported throughout the plant
- dissolved mineral salts diffuse into the root cell
- mineral salts diffuse into the xylem from the root cell
- the mineral salts are transported to the rest of the plant via the xylem
what is the process of the water being transported throughout the plant
- water enters the root cell by osmosis
- water moves across the roots from cell to cell by osmosis
- water is transported to the rest of the plant via the xylem
State the process that occurs at the stomata
diffusion
