Given below from (i) to (iv) are some food items. Boiled and mashed potato Glucose solution A slice of bread Mustard oil Which of the above will give a blue-black colour when tested with iodine? (a) (i) and (ii) (b) (i) and (iii) (c) (ii) and (iii) (d) (iii) and (iv)
ScienceClass 7CBSEAnswered 27 Mar 2026
Answer
Soln:
The answer is (b) (i) and (iii)
Explanation:
Mashed potato and bread are rich in starch. On adding iodine, it reacts with starch to give a blue-black colour.
Suggested Q&A
Science · Class 7- ScienceClass 7In towns and cities, generally, bore wells have to be dug very deep to get water as compared to bore wells dug in villages. Give suitable reasons.
- ScienceClass 7Gardeners gently dig up the soil around the roots of garden herbs (plants) frequently. Give reasons.
- ScienceClass 7Why is soil erosion relatively less in dense forests as compared to barren, open fields?
- ScienceClass 7Continuously water-logged soils are disadvantageous for plant growth. Why?
- ScienceClass 715. Match the animals in Column I with their natural place of dwelling (habitat) in Column II. Column-I Column-II a) Earthworm i) Sand and beaches b) Garden Lizard ii) Burrows in soil c) Crab iii) Deep, narrow holes in dry soils d) Rodents iv) Surface of soil e) Scorpion v) Surface of shaded moist soils f) Snails and snugs vi) A horizon of moist soils
- ScienceClass 7Rajasthan is a desert state in India. Once while travelling to Rajasthan by train, Boojho observed several streams and rivulets of rainwater during the journey, but to his surprise, he did not see streams of water in the desert region even during rains. Help Boojho find a suitable explanation for this.