WAEC - Biology (2006 - No. 32)
Which of the following food substances would produce a translucent mark when rubbed on a white paper?
Potato
Beans
Mango
Groundnut
Explication
If a food sample is rubbed on a piece of paper and the paper becomes translucent and remains translucent even after it dries, it indicates the presence of fats in the tested food. Oils, butter, and cheese are rich sources of fat. Groundnut (oil) is a rich source of monounsaturated fats.