CG Board Class 8 Science Chapter 15 Solutions: How Much Food – What Type of Food (कितना भोजन – कैसा भोजन) – 2026-27

Given:**

• Volume of water per glass = 200 mL.
• 1 Litre = 1000 mL.
• Calculation:

1. Minimum required volume = 2 Litres = 2 × 1000 mL = 2000 mL.

Number of glasses = (2000 mL)/(200 mL) = 10 glasses

1. Maximum required volume = 3 Litres = 3 × 1000 mL = 3000 mL.

Number of glasses = (3000 mL)/(200 mL) = 15 glasses

• Conclusion: A healthy man must drink 10 to 15 glasses of water per day.

### Complete Table 15.1:

• Table Solution (English & Hindi):

| Carbohydrates | Fats | Proteins | Vitamins & Minerals |

| Rice, wheat, corn, maize, bajra, jawar, potato | Butter, Ghee, Oil | Pulses, Mutton, Fish, Egg, Soyabean | Carrot, Pumpkin, Papaya, gooseberry, green leafy vegetables, milk, egg, orange, tomato, mango, lemon |

### Complete Table 15.2:

• Table Solution (English & Hindi):

No, carbohydrate, protein, and fat are not present in all food items. Certain single-component food items contain only one specific nutrient (for example, sugar contains only carbohydrates, and refined oil or ghee contains only fats).

Yes, it is correct. Most natural food items contain a combination of multiple nutrients. For example, staple food grains like rice and wheat contain carbohydrates along with fats and vitamins, while eggs contain proteins, fats, vitamins, and minerals.

Fried food items like sev, bhajiya, or samosa contain oil/fats. When wrapped, the oil gets absorbed by the paper fibers, making the paper slippery and semitransparent (translucent). This property of paper becoming semitransparent when rubbed against a food item is the characteristic test for the presence of fats.

If a person does not get a balanced diet containing required amounts of carbohydrates, proteins, fats, vitamins, and minerals

1. The person’s body becomes weak and suffers from malnutrition.
2. Physical growth and mental development slow down.
3. The body’s repair mechanism for daily wear and tear gets hindered.
4. The immunity weakens, making the body highly vulnerable to deficiency diseases such as night blindness, beri-beri, scurvy, rickets, anemia, and goitre.

Vitamin A:**

• Sources: Milk, egg yolk, liver, green vegetables, tomato, carrot, papaya, and pumpkin.
• Deficiency Disease: Night blindness (inability to see in dim light/night).
• Vitamin B:
• Sources: Whole grains, mutton, milk, curd, butter, and eggs.
• Deficiency Disease: Beri-beri (weakened nervous system), anemia, and deformed vertebral column.
• Vitamin C:
• Sources: Gooseberry (amla), orange, lemon, guava, and citrus fruits.
• Deficiency Disease: Scurvy (bleeding gums and skin disorders).

(a) Incorrect.**

• Corrected Statement: Fibres (roughage) are essential for humans because they keep our digestive organs clean so that the digestive process goes on smoothly.
• (b) Incorrect.
• Corrected Statement: Costly food items are not necessarily more nutritious; inexpensive items like green leafy vegetables, carrots, gooseberries (amla), and guavas contain high nutritional value.
• (c) Incorrect.
• Corrected Statement: Children, pregnant women, and lactating mothers need a larger amount of balanced diet for body growth and healthy development.
• (d) Incorrect.
• Corrected Statement: Potatoes contain a large amount of carbohydrates (starch), whereas proteins are rich in pulses, soybeans, milk, and eggs.
• (e) Incorrect.
• Corrected Statement: Most food items contain more than one nutrient in them.
• (f) Incorrect.
• Corrected Statement: A balanced diet must contain all required nutrients (carbohydrates, proteins, fats, vitamins, and minerals) in appropriate proportions.
• (g) Incorrect.
• Corrected Statement: Our body needs carbohydrates, proteins, and fats in large quantities, whereas vitamins and minerals are needed only in minute quantities.

Drying removes moisture from food items, inhibiting microbial growth and preventing spoilage. Other food items preserved by drying include

1. Fenugreek (methi) and Mint (pudina) leaves
2. Bitter gourd (karela) and Cauliflower pieces
3. Raw mango slices (for making amchur powder)
4. Potato chips, Papad, and Badi (gram flour dumplings)
5. Food grains, pulses, and dry fruits (raisins, dates)

Salt acts as a natural preservative by absorbing moisture and preventing bacterial growth. Food items preserved in salt include

1. Raw mango slices (for pickles)
2. Gooseberry (Amla) and Lemon
3. Tamarind (Imli)
4. Raw Jackfruit pieces
5. Fish and Meat (by salting/curing)

Insecticides used in fields:** Chemical insecticides like DDT, BHC, or Malathion are sprayed on standing crops and vegetables to protect them from insect damage.

• Methods used at home for grain preservation:

1. Mixing dried Neem leaves into grain storage containers.
2. Adding cloves, matchsticks, or camphor.
3. Applying small quantities of edible oils (castor oil or mustard oil) to pulses.
4. Placing safe inorganic tablets (like chalk/mercury tablets wrapped tightly in cloth) inside storage bins.

Possible Reasons:**

1. Lack of awareness about proper nutrition and balanced diet.
2. Poverty and financial inability to afford diverse food items.
3. Faulty eating habits, addiction to junk food, and the misconception that only expensive foods are nutritious.

• Our Advice:

1. Educate them that a balanced diet does not need to be costly; low-cost local items like green leafy vegetables, amla, guava, jaggery, and sprouted pulses provide rich nutrition.
2. Consume a mixed diet containing locally available grains, pulses, seasonal fruits, and vegetables.
3. Avoid excessive fried foods, sweets, junk food, tea, or coffee as they damage the digestive system.

This statement is incorrect. Water that appears clean and clear to the naked eye may still harbor microscopic disease-causing bacteria, viruses, parasites, and dissolved chemical impurities. Therefore, visual clarity alone does not guarantee that water is potable. Water must be purified by boiling, filtration, or chlorination to ensure it is completely safe for drinking.

The main methods used to convert raw water into safe potable water are

1. Physical Filtration: Using candle-type household filters or modern multi-stage purifiers to remove suspended physical impurities.
2. Boiling: Boiling water vigorously for 10 to 15 minutes kills harmful bacteria and germs.
3. Chlorination (Chemical Method): Adding controlled amounts of chlorine tablets or bleaching powder to disinfect the water.
4. Municipal Water Treatment: Large-scale settling, filtration, and chemical disinfection before supplying to households.