Plant Organ Systems

biology

Xylem adaptations

• when cells die form long hollow tubes to transport water + minerals

• spirals of lignin strengthen the plant and help it withstand pressure

xylem functions

• transport tissue

• carries water + mineral ions from roots to photosynthesising cells

phloem functions

• carry sucrose + amino acids from photosynthesising cells to where they are stored/used

phloem adaptations

• sieve tubes

• companion cells

companion cells

• transport requires energy- help load + unload sucrose + amino acids in + out of phloem vessels

sieve tubes

• no nuclei + has perforated end wall so its cytoplasm connects cells together

transpiration

loss of water vapour from the leaves through diffusion

transpiration stream functions (4 points)

• transport mineral ions

• provides water to keep cells turgid

• water to leaf cells for photosynthesis

• cools leaves for evaporation

translocation

the transport of sugars and amino acids from where they are produced to where they are used/stored

root hair cells function

takes in water and mineral ions

root hair cells adaptation (4 points)

• large surface area-long thin protrusion- more sa for osmosis and active transport

• large vacuole w/ concentrated solutio- draws water in, osmosis

• lots of mitochondria- release energy- AT

• no chloroplasts

stomata + guard cells

• control gas exchange

• control water loss