PLANT PHYSIOLOGY
TRANSPORT IN PLANT
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
that sink strength drives transport in the phloem.
|
|
|
the water potential gradient in the sieve elements drives transport
|
|
|
that transport in treachery elements is pressure dependent
|
|
|
the pressure gradient between the sieve elements at the source and the sink drives phloem transport.
|
Detailed explanation-1: -In very general terms, the pressure flow model works like this: a high concentration of sugar at the source creates a low solute potential (s), which draws water into the phloem from the adjacent xylem. This creates a high pressure potential (p), or high turgor pressure, in the phloem.
Detailed explanation-2: -Phloem movement occurs by mass flow from sources of sugar to sugar sinks. The phloem movement is bidirectional but unidirectional in xylem cells.
Detailed explanation-3: -Answer. Translocation is the process by which assimilates from photosynthesis are moved around the plant, from where they are made to where they are needed. The place where these assimilates are produced is called the source, and the place they are moved to is called the sink.
Detailed explanation-4: -A model, called the pressure flow model, describes how sucrose concentrations determine the direction of the flow. Two types of cells-source cells and sink cells-play roles in the transport of solutions in the phloem. Source cells produce sucrose and load it into the phloem.