please explain whole 95
95. Which of the following is not correct w.r.t. mass flow hypothesis
(1)Water comes into phloem from adjacent xylem cells
(2) Movement of sucrose into sieve tube via companion cells
(3) At sink osmotic pressure must be increased
(4) Movement of sugars in the phloem begins at the source
Dear student,
Answer is 3) At the sink osmotic pressure must be increased.
Active loading of sugar occurs at the sieve tube element which leads to the diffusion of water from the xylem into sieve tube element. Due to increase in osmotic pressure sugar moves to low pressure. Osmotic pressure must be reduced at the sink. Active or passive unloading of sugar occurs due to which water diffuses from sieve tube element into xylem. The pressure gradient in sieve tube element causes translocation of sugar from source to sink.
Regards
Answer is 3) At the sink osmotic pressure must be increased.
Active loading of sugar occurs at the sieve tube element which leads to the diffusion of water from the xylem into sieve tube element. Due to increase in osmotic pressure sugar moves to low pressure. Osmotic pressure must be reduced at the sink. Active or passive unloading of sugar occurs due to which water diffuses from sieve tube element into xylem. The pressure gradient in sieve tube element causes translocation of sugar from source to sink.
Regards