BI-1427
Food tests
Biology · Secondary 4 · Hard · Food tests
A student tests three food samples, P, Q and R, using Benedict’s solution, biuret solution and ethanol emulsion.
- P gives a brick‑red precipitate with Benedict’s, stays blue with biuret, and turns milky with ethanol.
- Q stays blue with Benedict’s, turns violet with biuret, and stays clear with ethanol.
- R stays blue with Benedict’s, stays blue with biuret, and stays clear with ethanol.
Which row shows the main nutrient present in each food?
P Q R
- P gives a brick‑red precipitate with Benedict’s, stays blue with biuret, and turns milky with ethanol.
- Q stays blue with Benedict’s, turns violet with biuret, and stays clear with ethanol.
- R stays blue with Benedict’s, stays blue with biuret, and stays clear with ethanol.
Which row shows the main nutrient present in each food?
P Q R
- P fats, Q proteins, R none of these nutrients
- P carbohydrates, Q fats, R proteins
- P proteins, Q carbohydrates, R fats
- P carbohydrates, Q proteins, R fats
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