117: Regular intake of fresh fruits and vegetables is recommended in the diet since they are a good source of antioxidants. How do antioxidants help a person maintain health and promote longevity?
(a) They activate the enzymes necessary for vitamin synthesis in the body and help prevent vitamin deficiency.
(b) They prevent excessive oxidation of carbohydrates, fats and proteins in the body and help avoid unnecessary wastage of energy.
(c) They neutralize the free radicals produced in the body during metabolism.
(d) They activate certain genes in the cells of the body and help delay the ageing process.
Explanation:
Antioxidants are substances that may protect cells from the damage caused by unstable molecules known as free radicals. Damage due to free radicals damage may lead to cancer. Antioxidants interact with and stabilise free radicals and may prevent some of the damage free radicals otherwise might cause. Examples of antioxidants include beta-carotene, lycopene, vitamins C, E, and A, and other substances.
Fruits and vegetables provide a range of antioxidants, vitamins A, C and E, carotenoids and flavonoids. Fruits and vegetables that have comparatively high levels of antioxidants include apples, grapefruit, green grapes, oranges, peach, red plums, strawberries, beetroot sprouts cauliflower, green cabbage, lettuce onion, spinach and tomatoes.
Antioxidants help to reduce to risk of cancer, heart attack and stroke.
118: With reference to the Indian Regional Navigation Satellite System (IRNSS), consider the following statements :
1. IRNSS has three satellites in geostationary and four satellites in geosynchronous orbits.
2. IRNSS covers entire India and about 5500 sq. km beyond its borders.
3. India will have its own satellite navigation system with full global coverage by the middle of 2019.
Which of the statements given above is/are correct ?
(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) None
119: Consider the following phenomena :
1. Light is affected by gravity.
2. The Universe is constantly expanding.
3. Matter warps its surrounding space-time.
Which of the above is/are the prediction/predictions of Albert Einstein's General Theory of Relativity, often discussed in media ?
(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3