Q. Why the transport of organic food through phloem is bidirectional?
A) Roots serve as source while leaves are the sink region
B) Source and sink region are irreversible
C) The relationship between the two region (source and sink) is variable and is dependent on season and plant needs
D) Translocation of organic solute is regulated by energy
Explanation
Long distance transport of the substances takes place through bulk flow system. Organic nutrients are supplied over long distance transport by phloem tissue from source to sink region. The direction of transport of these organic nutrients can be upward or downward, i.e., bidirectional. This is due to the variable relationship between synthesis region or source site and sink or utilisation region
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.