According to the pressure flow hypothesis:
$A.$ Phloem loading produces a hypertonic condition in the sieve tubes.
$B.$ Water potential gradient facilitates the mass movement in the phloem.
$C.$ Phloem unloading is a passive process.

Consider the following statements and choose the correct option from the codes given below:
$I.$ Loading of phloem is related to the increase of sugar in phloem.
$II.$ Active loading of sugar in the sieve tube of phloem is driven by a proton pump.
$III.$ Pressure may be positive or negative in sieve tube cells.
$IV.$ Water and solutes move through the sieve tube against the pressure gradient.
$V.$ Cytoplasmic strands pass through the holes in sieve plates and form continuous filaments.

Which of the tissue is more important for the translocation of sucrose?

Sucrose moves into sieve tube elements by

In phloem,the flow is always from

If a stem is girdled,what happens?