Question

The carbohydrates synthesized in the leaves are transported through sieve tubes mostly in the form of

• A. glucose
• B. sucrose
• C. starch
• D. cellulose

Answer 1

Answer: (B)

sucrose

After sugars are produced in photosynthesis, these sugars must be transported to other parts of the plant for use in the plant's metabolism. Part of the pressure-flow theory is that the sucrose produced is moved by active transport into the companion cells of the phloem in leaf veins. Sucrose and starch are more efficient in energy storage when compared to glucose and fructose, but starch is insoluble in water. So plants use the sucrose as a medium to transfer energy. Inside the cells, sucrose is converted back to glucose and fructose. Energy is yielded when it is needed.

So, the correct option is, 'Sucrose'.