Transport In Plants Flashcards
What is one problem with the mass flow hypothesis?
- Treatment with cyanide stops translocation (cyanide is a respiratory inhibitor)
- Can’t just be diffusion acting as mass flow is 10,000 times faster than diffusion
Where does gaseous exchange occur in plants?
Through pores in the leaves called stomata
What does Phloem consist of?
Companion cells and sieve tubes
What is a benefit of the waxy cuticle later on leaves?
It reduces water loss
What is the cohesion-tension theory?
It’s how water moves up plants
What is present in the walls of the endodermis?
The Casparian Strip
What takes up the water from the soil?
Specialised root hair cells
What does the mass flow suggest occurs passively?
The movement of photosynsate from source to sink
What is transpiration?
The evaporation of water from the leaves into the atmosphere
What are vascular bundles made up of?
Xylem and phloem
What strengthens and waterproofs the walls of the xylem?
Lignin
What leads to the guard cells becoming turgid?
The uptake if potassium ions reducing the water potential and causing water to flow into the guard cells by osmosis
What is the form of the sugar in plants?
The disaccharide sucrose
