Question

The movement of sugars produced during photosynthesis is said to be from source to sink. Which of the following does not represent a correct source-sink pair?

• A. Leaves-stem
• B. Stem-roots
• C. Mature fruit-developing leaf
• D. Leaves-developing fruit
• E. Developing fruit-stem

Answer 1

Answer: (E)

Developing fruit-stem

A source is the region of the plant where sugar is synthesized and sink is the part of the plant where sugar is translocated.

A. Leaves synthesize sugar by photosynthesis and the sugar is translocated to stem. Hence, leaves are source and stem is sink.

B. Stem store the sugars for where it is transported to the roots. Hence, the stem is a source and roots are sinks.

C. Mature fruit has sugars which are transported to the developing leaf. Hence, mature is a source and growing leaf is a sink.

D. Leaves synthesize sugar by photosynthesis and the sugar is translocated to the developing fruit. Hence, leaves are the source and developing fruit is a sink.

E. Developing fruit will accumulate sugars transported from the stem. Hence, the stem is the source and developing fruit is a sink.

Hence option E doesn't represent a correct source-sink pair. So, the correct answer is 'Developing fruit-stem'.