Olympiad Test: Components of Food - Class 6 Science Free MCQ with solutions

Calcium is an essential mineral for the development and maintenance of strong bones and teeth. It helps in the formation of bone structure and also plays a vital role in muscle function, nerve transmission, and blood clotting.

• Iodine is important for thyroid function.
• Sodium is essential for fluid balance and nerve function.
• Iron is necessary for oxygen transport in the blood.

So, the mineral that is essential for strong bones and teeth is Calcium.

All the statements are correct with regard to our diet:

• A: Eat a diet rich in carbohydrates and proteins.
  Carbohydrates provide energy, while proteins are essential for growth, repair, and maintaining muscle mass.
• B: Drink plenty of water.
  Water is crucial for hydration, digestion, and various body functions.
• C: Eat green vegetables every day.
  Green vegetables are packed with vitamins, minerals, and fiber, which are important for overall health.

Therefore, the correct answer is D) All of these.

When iodine solution is applied to starch, it turns blue-black. Cooked rice contains starch, and iodine reacts with it to produce this color change.

• Vegetable oil does not cause any color change in rice.
• Benedict's solution is used to test for reducing sugars, and it would not turn rice blue-black.
• Nitrate solution is used to test for the presence of nitrate ions, and it does not cause a color change with rice.

Therefore, the liquid that caused the rice to turn blue-black is Iodine solution.

The correct matches based on common nutritional knowledge are as follows:

• Amla is a rich source of Vitamin C. So, (i) matches with (c).
• Carrot is known for its high content of Vitamin A. So, (ii) matches with (d).
• Milk is a primary source of Calcium. So, (iii) matches with (a).
• Salt is often iodized to provide Iodine. So, (iv) matches with (b).

Thus, option b correctly pairs each item in Column I with its appropriate source or nutrient in Column II.

A deficiency in Vitamin C leads to a condition known as scurvy. The symptoms of scurvy include:

• Bleeding of gums
• Slow healing of wounds
• Aching limbs and joints

Vitamin C is essential for the production of collagen, which is necessary for healthy skin, blood vessels, and tissues. Without enough Vitamin C, the body's tissues weaken, leading to the symptoms mentioned above.

• Vitamin A deficiency leads to night blindness and skin issues.
• Vitamin B deficiency can lead to various problems like fatigue, nerve damage, and anemia.
• Vitamin D deficiency leads to bone weakness, rickets in children, and osteomalacia in adults.

Therefore, the correct answer is (C) Vitamin C.

• Vitamin A → Night blindness: Correct. Vitamin A deficiency can lead to night blindness, a condition where individuals struggle to see in low light.
• Vitamin B₁ → Scurvy: Incorrect. Vitamin B1 (Thiamine) deficiency leads to beriberi, not scurvy. Scurvy is caused by a deficiency in Vitamin C.
• Iron → Anaemia: Correct. Iron deficiency leads to iron-deficiency anemia, where the body cannot produce enough healthy red blood cells.
• Vitamin D → Rickets: Correct. A deficiency in Vitamin D can cause rickets in children, a condition characterized by weak bones.

So, the incorrect pairing is (B) Vitamin B₁ → Scurvy.

A nutrient is any substance that the body needs for growth, maintenance, and repair of tissues, and for regulating body processes. Nutrients are found in food and are essential for proper body functioning.

• A is correct because nutrients are substances found in food that are essential for the body's proper functioning, including providing energy, supporting metabolism, and aiding in growth and repair.
• B is incorrect because nutrients are not substances that alter body functioning in a negative way. They are essential for normal body functions.
• C and D are incorrect because nutrients are specifically helpful to the body, unlike substances that are not useful for body functioning.

Thus, the correct answer is (A) Constituent of food that helps in body functioning.

Both fats and carbohydrates are classified as energy-giving foods because they provide the body with the energy required for various functions:

• Carbohydrates are the body's primary source of energy. They are broken down into glucose, which provides immediate energy.

• Fats are also an important source of energy, especially for long-term energy storage. They provide more energy per gram compared to carbohydrates.

Therefore, the correct answer is (C) both (a) and (b).

• Beans, peas, pulses, and meat are all rich in proteins. Proteins are essential for building and repairing tissues, and they are also important for immune function and enzyme production.

• Fats are found in foods like oils, butter, and nuts.

• Vitamins are found in fruits, vegetables, and dairy products.

• Carbohydrates are mainly found in foods like bread, rice, and potatoes.

Thus, the correct answer is B) Proteins.

The reaction described—where the white of an egg turns violet upon adding copper sulphate and caustic soda—is a test for the presence of proteins. This is known as the biuret test, which turns violet in the presence of proteins due to the chemical reaction between copper ions and the peptide bonds in proteins.

• Starch is tested using iodine solution, which turns blue-black in the presence of starch.
• Fats are tested using Sudan III dye, which stains fats red.
• Vitamins are not detected in this manner.

Therefore, the correct answer is (B) Proteins.

When the skin is exposed to sunlight, specifically ultraviolet (UV) rays, the body produces Vitamin D. This vitamin is essential for the absorption of calcium and phosphorus, which are necessary for strong bones and teeth.

• Vitamin A is obtained from foods like carrots and leafy vegetables.
• Vitamin B includes a group of vitamins such as B1, B2, B6, and B12, which are obtained from various foods.
• Vitamin K is important for blood clotting and is found in foods like leafy greens.

Thus, the correct answer is (C) Vitamin D.

a) Vitamin A → Bananas are not a significant source of Vitamin A. Carrots, papaya, spinach are rich in Vitamin A.

b) Calcium → Bananas contain only a small amount of calcium, but they are not known for it. Milk and dairy are main sources.

c) Potassium → This is the most important nutrient in bananas. They are famous for being “potassium-rich fruits.”

d) Iodine → Bananas don’t contain iodine in any notable amount. Iodized salt and seafood are primary sources.

1. Spinach → Iron (c): Spinach is rich in iron, which is essential for producing hemoglobin in the blood.

2. Milk → Calcium (d): Milk is an excellent source of calcium, which is vital for strong bones and teeth.

3. Salt → Iodine (b): Salt, especially iodized salt, is a common source of iodine, necessary for proper thyroid function.

4. Whole grain → Roughage (a): Whole grains are rich in fiber (roughage), aiding digestion and preventing constipation.

Thus, the correct matching is:
(i) Spinach → c
(ii) Milk → d
(iii) Salt → b
(iv) Whole grain → a

This corresponds to Option D.

Vitamin C (Ascorbic acid) is water-soluble and highly sensitive to heat, light, and air. It is easily destroyed during cooking, especially when foods are exposed to high temperatures or long cooking times. This is why it's recommended to eat some fruits and vegetables raw to retain their Vitamin C content.

• Vitamin A is fat-soluble and more stable during cooking.
• Vitamin D is also fat-soluble and not easily destroyed by heat.
• Vitamin K is relatively heat-stable and is not lost easily during cooking.

Therefore, the correct answer is (B) Vitamin C.

Carrots are a rich source of Vitamin A in the form of beta-carotene, which the body converts into Vitamin A. Beta-carotene is a plant-based compound and is known for its antioxidant properties. Additionally, carrots are fat-free, making them a healthy option for boosting Vitamin A intake.

• Potato contains some vitamins and minerals but is not a significant source of Vitamin A.
• Honey does not contain Vitamin A in substantial amounts.
• Eggs are rich in Vitamin A but also contain fats, especially in the yolk.

Therefore, the correct answer is (A) Carrot.

A protein deficiency can lead to a condition called kwashiorkor, which is characterized by symptoms such as:

• Swelling of the face (due to edema, which is the accumulation of fluid)
• Edema in the legs, arms, and abdomen
• Stunted growth and weak muscles

Protein is essential for growth, tissue repair, and maintaining fluid balance in the body. Without enough protein, the body cannot maintain this balance, leading to swelling.

• Obesity is related to an imbalance in calorie intake (especially fats and carbohydrates), not protein deficiency.
• Bent bones could be a sign of a deficiency in Vitamin D or calcium, not proteins.
• Poor vision is generally associated with a deficiency in Vitamin A, not proteins.

Thus, the correct answer is (A) Swelling of face.

Roughage, also known as fiber, is an important component of the diet that comes from plant-based foods like fruits, vegetables, whole grains, and legumes. It plays a crucial role in:

• Preventing constipation by adding bulk to the stool and aiding in its movement through the digestive tract.
• Maintaining digestive health, helping to regulate bowel movements and prevent conditions like diverticulosis.

While roughage is essential for digestive health, it does not directly build or repair tissues, produce hemoglobin, or maintain overall body health in the same way that proteins, iron, and other nutrients do.

Therefore, the correct answer is (A) Prevents constipation.

Vitamin D is essential for helping the body absorb calcium, which is vital for maintaining strong bones and teeth. It can be obtained through exposure to sunlight and is also present in foods like eggs, butter, and milk.

• Vitamin E is an antioxidant that helps protect cells from damage and is found in foods like nuts, seeds, and vegetable oils.
• Vitamin K is important for blood clotting and is found in green leafy vegetables, broccoli, and certain oils.
• Vitamin C is essential for the growth and repair of tissues and is found in fruits like oranges, strawberries, and bell peppers.

As per the solution, Vitamin D helps the body use calcium for bones and teeth, and it is found in sunlight, eggs, butter, and milk.

Thus, the correct answer is (B) Vitamin D.

Nutrients are classified into 5 types: carbohydrates, proteins, fats, vitamins, and minerals. While water and dietary fibre (roughage) are important for health, they are not classified as nutrients. Therefore, the correct answer is 5.

Pulses (such as lentils, beans, chickpeas, and peas) are a rich source of proteins. They are an important part of a vegetarian diet and help in building and repairing tissues, making enzymes and hormones, and supporting overall growth.

• Vitamins are present in fruits, vegetables, and dairy products, not primarily in pulses.
• Fats are present in oils, nuts, and seeds, but pulses contain very little fat.
• Carbohydrates are also present in pulses, but their primary nutrient content is protein.

Therefore, the correct answer is (D) Proteins.