Mass Transport Animals 🐆 Flashcards
(11 cards)
What substances are transported in the xylem ?
Water and inorganic ions
What substances are transported in the phloem?
Organic solutes
What direction do the contents in the xylem flow?
Upwards from roots to shoots and leaves
What direction do the contents of the phloem move in ?
Any direction source to sink(s)
Order the layers of roots from outwards to inwards.
Root hair cells
Epidermis
Cortex
Endodermis
How does water enter the root hair cells?
Water enters through the root hair cells within the epidermis via osmosis
How are root hair cells adapted to water absorption?
-hair like extensions that increase their surface area to increase the uptake of water and increase the area for aquaporins, channel and carrier proteins
-thin cellulose cell walls so they have a short diffusion distance
How to root hair cells transport ions from their membranes to their cytoplasm?
actively transport using energy from ATP hydrolysis via carrier proteins
What happens to the rate of ion absorption if the soil is waterlogged ?
-waterlogged soil has no air spaces between soil particles
- air spaces contain O2
-O2 is needed for aerobic respiration in mitochondria of the root hair cells to synthesise ATP
-less ATP synthesis results in less ATP energy transferred for aerobic respiration
Xylem Structure and Function:
(S) Dead Cells that form hollow tubes with no cytoplasm. (F) faster water flow with less resistance because of no impediment from organelles
(S) End walls break down, forms continuous tube. (F) so a continuous column of water can form (due to cohesion)
(S) Xyelm Pits. (F) allow water to move laterally between xyelm vessels to get around blocked vessels.
(S) cell walls strengthened with lignin. (F) makes xylem water proof and rigid provides support to withstand tension and enables adhesion of water
Why do plants need to conserve water?
They are extra terrestrial organisms and need water for growth and aerobic respiration
