HARD
AS and A Level
IMPORTANT
Earn 100
Explain how water moves from the soil into a root hair cell.
Important Questions on Transport in Plants
HARD
AS and A Level
IMPORTANT
Explain how water moves from one root cortex cell to another.
HARD
AS and A Level
IMPORTANT
Explain how water moves from a xylem vessel into a leaf mesophyll cell.
HARD
AS and A Level
IMPORTANT
Arrange the following in order of water potential. Use the symbol to mean 'greater than'.
Dry atmospheric air, Mesophyll cell, Root hair cell, Soil solution, Xylem vessel contents
HARD
AS and A Level
IMPORTANT
An instrument called a dendrogram can be used to measure small changes in the diameter of a tree trunk. The instrument usually shows that the diameter of the tree trunk is at its lowest during daylight hours and at its greatest at night. Suggest an explanation for these observations.
HARD
AS and A Level
IMPORTANT
Explain how active loading of sucrose into companion cells leads to a relatively high pH of about pH 8 in the cytoplasm of the companion cells.
HARD
AS and A Level
IMPORTANT
Explain how active loading of sucrose into companion cells leads to negative charges inside the companion cells relative to the outside. (There is a difference in electric potential across the cell surface membrane, with a potential of about -150mV on the inside.
HARD
AS and A Level
IMPORTANT
Explain how active loading of sucrose into companion cells leads to the relatively large amounts of ATP present inside the companion cells.
MEDIUM
AS and A Level
IMPORTANT
Translocation of organic solutes takes place between sources and sinks. Briefly explain under what circumstances a seed could be a sink.
