Bulk flow is achieved due to a positive hydrostatic pressure gradient in _____and negative hydrostatic pressure gradient in _____ respectively.
Phloem and xylem
Bulk flow occurs due to positive hydrostatic pressure gradient in phloem and organic solutes are pushed. In xylem, water along with inorganic solutes are pulled by the negative hydrostatic pressure gradient created by the transpirational loss of water from the leaves.