CBSE Class 10 Biology Food and Nutrition MCQs Set 05

Answer: (b) 240 kcal

Explanation:
1. Sleep needs about 72 kcal an hour, light work about 150 kcal and strenuous work about 240 kcal an hour.

Teacher's Note:
1. Learn the four anchor values: 72, 140, 150 and 240 kcal per hour.
2. Heavier work always means higher hourly energy use.

Answer: (b) Maltose

Explanation:
1. Enzymes break starch into maltose (two glucose units) when starchy seeds germinate.

Teacher's Note:
1. Maltose is also called malt sugar because malt is germinated barley.
2. Lactose is milk sugar and sucrose is cane sugar.

Answer: (a) proteins

Explanation:
1. Spirulina contains a very high proportion of protein, so it is used as a protein supplement.

Teacher's Note:
1. Soyabean and Spirulina are two non-animal protein-rich foods.
2. Do not confuse it with a carbohydrate source like cereals.

Answer: (a) making the surface water proof

Explanation:
1. Waxes coat the skin of animals and the stems, leaves and fruits of plants and make them waterproof; they also reduce water loss.

Teacher's Note:
1. Waxes are chemically inert lipids with a protective role.
2. Transpiration is reduced, not promoted, by the wax coat.

Answer: (d) testosterone

Explanation:
1. Testosterone is a steroid hormone made in the testes; oestrogen and progesterone come from the ovaries and aldosterone from the adrenal cortex.

Teacher's Note:
1. Steroid hormones are lipids derived from cholesterol.
2. Link each steroid hormone to its gland.

Answer: (b) iodine

Explanation:
1. Sea fish and other sea food are rich in iodine, which is needed to make thyroxine.

Teacher's Note:
1. Iodine deficiency causes goitre, which is rare in coastal people.
2. Iodised salt is the other common source.

Answer: (c) Fats

Explanation:
1. Lipases split fats into fatty acids and glycerol, so without lipases fats stay undigested.

Teacher's Note:
1. Proteases act on proteins and amylases on starch.
2. Enzyme names often end in -ase and show the substrate: lip- for fat.

Answer: (a) vitamin C

Explanation:
1. Germination makes vitamin C in pulses and grams rise sharply, so sprouted beans are a good source of it.

Teacher's Note:
1. Sprouting also forms maltose, amino acids and fatty acids.
2. Eating sprouts raw or lightly cooked protects the vitamin.

Answer: (d) D

Explanation:
1. Vitamin D occurs in animal foods such as fish-liver oil, egg yolk, milk and butter and is made in our skin in sunlight; plant foods do not supply it.

Teacher's Note:
1. Plant foods give carotene, which the body turns into vitamin A.
2. Sunlight on the skin is the easiest source of vitamin D.

Answer: (a) 9.2 kcal

Explanation:
1. Fat gives about 9.2 kcal per gram, while carbohydrate and protein give about 4.1 kcal per gram each.

Teacher's Note:
1. Fat gives roughly double the energy of the same weight of carbohydrate.
2. That is why fat is the body's compact energy store.

Answer: (a) lactometer

Explanation:
1. A lactometer floats in milk and its reading shows the density; added water lowers the reading below 1.026.

Teacher's Note:
1. A calorimeter measures heat, a hygrometer humidity and a sphygmomanometer blood pressure.
2. The word lacto- refers to milk.

Answer: (b) Anaemia

Explanation:
1. Iron deficiency lowers haemoglobin, which causes anaemia with loss of appetite, tiredness and weakness.

Teacher's Note:
1. Marasmus is a wasting disease of infants and shows thin limbs and ribs.
2. Iron-rich foods are spinach, jaggery and dates.

Answer: (d) all of the above

Explanation:
1. Seasonal fruits, greens and coarse grains such as bajra are cheap and supply vitamins, minerals and proteins, so all three help.

Teacher's Note:
1. Cheap local foods can balance a poor diet.
2. When every option is useful, choose all of the above.

Answer: (a) spinach

Explanation:
1. Spinach (palak) is rich in iron, calcium and vitamins; carrots mainly give vitamin A and citrus fruits give vitamin C.

Teacher's Note:
1. Jaggery and dates are other good iron sources.
2. Vitamin C helps the body absorb iron.

Answer: (a) carrots

Explanation:
1. Carrots contain carotene, which is changed into vitamin A, and a shortage of vitamin A causes night blindness.

Teacher's Note:
1. Yellow and orange fruits and vegetables are good sources of carotene.
2. Lime supplies vitamin C, not vitamin A.

Answer: (c) iron

Explanation:
1. Iron is needed to make haemoglobin, so shortage of iron causes anaemia.

Teacher's Note:
1. Calcium deficiency affects bones and teeth.
2. Vitamin B12 is also needed for red blood cells.

Answer: (a) Excessive washing of grains

Explanation:
1. Washing grains again and again removes water-soluble vitamins and minerals; the other three practices save nutrients.

Teacher's Note:
1. Do not throw away cooking water that contains dissolved vitamins.
2. Covering the pot and using little water cuts the loss of vitamin C.

Answer: (b) kesari dal

Explanation:
1. Kesari dal and the dye metanil yellow are the common dal adulterants. Lead chromate is added to turmeric, papaya seeds to pepper and argemone seeds to mustard.

Teacher's Note:
1. Match each food with its adulterant to avoid mix-ups.
2. A few drops of hydrochloric acid turn dal pink if metanil yellow is present.

Answer: (c) banana

Explanation:
1. Banana is cheap and is a good source of carbohydrate along with several vitamins and minerals.

Teacher's Note:
1. Seasonal and local fruits are the best choice for a poor family.
2. Guava and sweet lime are rich mainly in vitamin C.

Answer: (a) glycogen

Explanation:
1. Surplus glucose is stored as glycogen in the liver and muscles, and after that as fat. Starch is the plant store.

Teacher's Note:
1. Glycogen is the animal counterpart of starch.
2. Continued excess intake leads to fat deposits and obesity.