CAIE IGCSE Biology 8.4.3 Some Parts of a Plant May Act Questions
Practise explaining why a leaf, root or storage organ can switch between source and sink roles over time.
- Syllabus
- 2026–2028
- Course
- Biology 0610
Practise explaining why a leaf, root or storage organ can switch between source and sink roles over time.
Aphids are arthropods.
Aphids insert their mouthpieces into the phloem in the stem of a plant to feed.
An aphid is shown in Fig. 2.1.
Fig. 2.1
magnification ×22
Fig. 2.3 shows a potato plant growing in the spring and then in the summer.
Fig. 2.3
Explain how translocation changes between spring and summer in the potato plant shown in Fig. 2.3.
Use the terms source and sink in your answer.
any four from:
in spring the (growing) shoot is the sink and the, tuber / potato, is the source ;
glucose / sucrose needed for, respiration / growth
or
amino acids / protein, for growth ;
in summer
the leaves are the source and the, tuber / potato, is the sink ;
leaves photosynthesise to, produce glucose / starch
or
leaves photosynthesise to transfer (light) energy (to chemical energy) ;
general:
(correctly named) sources are part of the plants that release sucrose / glucose / amino acids ;
(correctly named) sinks, use / store, sucrose / glucose / amino acids / starch / protein ;
the source and sink are different in spring and summer ;