Question 3
After the starch test on a variegated leaf, where is the blue-black colour seen?
The right answer is the one marked above.
Only where the leaf had been green. Starch was not produced in the white places, because chlorophyll is not contained there and photosynthesis did not take place.
This is the chapter’s definition proving itself: one group of cells photosynthesised and the group beside it did not, and nothing distinguishes them but the pigment.