Q1. How dehydration helps in the preservation of food?
(a) Growth of micro-organism is checked
(b) Nutrients are concentrated
(c) Surface of food stuffs becomes hard
(d) Chemical reactions stop in the absence of water
(UPSC Prelims 1981)
Answer: (a) Growth of micro-organism is checked
Explanation: Dehydration removes moisture, which is essential for the growth of bacteria, fungi, and other microbes. By eliminating water, food becomes less prone to spoilage, making it a reliable method for long-term preservation.
Q2. What is done to raise the dough while making bread?
(a) Alcohol is added
(b) Yeast is added
(c) Carbon dioxide is passed
(d) Air is passed
(UPSC Prelims 1981)
Answer: (b) Yeast is added
Explanation: Yeast ferments the sugars in flour, producing carbon dioxide that causes the dough to rise. This process creates air pockets, giving bread its soft and fluffy texture. Yeast is a key agent in leavening.
