Nutrients: Functions MCQs Quiz | Class 9

This is a multiple-choice quiz for Class 9 Home Science (Code 064), Unit IV: Food, Nutrition and Health. The questions in this quiz focus on the concept-based functions of major nutrients like carbohydrates, proteins, fats, vitamins, and minerals. Attempt all questions and click ‘Submit Quiz’ to see your score. You can also download a PDF of your answers after completing the quiz.

Understanding the Functions of Nutrients

Nutrients are essential substances that our bodies need to function, grow, and maintain health. They are broadly classified into macronutrients (required in large amounts) and micronutrients (required in small amounts). Understanding their specific roles is fundamental to making healthy food choices.

Key Functions of Major Nutrients

1. Carbohydrates

Often called “energy-giving foods,” carbohydrates are the body’s primary source of fuel. They are broken down into glucose, which is used by cells for energy. They are essential for the brain, central nervous system, and muscles during exercise.

  • Primary Function: To provide instant energy.
  • Sources: Cereals (wheat, rice), potatoes, fruits, sugar, and bread.

2. Proteins

Known as “body-building foods,” proteins are made of amino acids. They are crucial for building and repairing tissues, such as muscles, skin, and organs. They also play a role in making enzymes, hormones, and antibodies that fight infection.

  • Primary Function: Growth, repair, and maintenance of body tissues.
  • Sources: Pulses, milk and milk products, eggs, meat, and fish.

3. Fats

Fats are a concentrated source of energy, providing more than double the energy of carbohydrates. They insulate the body, protect vital organs, and are essential for absorbing fat-soluble vitamins (A, D, E, and K).

  • Primary Function: Provide stored energy, insulation, and absorption of certain vitamins.
  • Sources: Oils, butter, ghee, nuts, and oilseeds.

4. Vitamins and Minerals

These are “protective foods” required in small quantities for various metabolic processes. They help protect the body against diseases.

  • Vitamin A: Essential for good vision, especially in dim light.
  • Vitamin C: Important for a healthy immune system, skin, and gums. Prevents scurvy.
  • Vitamin D: Necessary for the body to absorb calcium, leading to strong bones.
  • Calcium (Mineral): Crucial for the formation and maintenance of strong bones and teeth.
  • Iron (Mineral): A key component of hemoglobin in red blood cells, which carries oxygen throughout the body. Its deficiency leads to anemia.

5. Water and Roughage

  • Water: Essential for life. It transports nutrients, removes waste, regulates body temperature, and is a medium for all metabolic reactions.
  • Roughage (Dietary Fiber): The indigestible part of plant foods. It does not provide nutrients but adds bulk to food, aids in digestion, and prevents constipation.

Nutrients Summary Table

Nutrient Main Function Common Food Sources
Carbohydrates Provides energy Cereals, bread, potatoes, fruits
Proteins Growth and repair of tissues Pulses, milk, eggs, meat, fish
Fats Energy reserve, insulation Oil, butter, nuts, ghee
Vitamins Protection against diseases Fruits, vegetables, milk, eggs
Minerals Building bones, blood, etc. Leafy greens, milk, salt, fruits

Quick Revision Points

  • Carbohydrates = Quick Energy.
  • Proteins = Body Building and Repair.
  • Fats = Stored Energy and Insulation.
  • Vitamin A = Vision.
  • Vitamin C = Immunity and Gums.
  • Vitamin D = Calcium Absorption for Bones.
  • Calcium = Strong Bones and Teeth.
  • Iron = Formation of Hemoglobin in blood.
  • Roughage = Proper Digestion.

Extra Practice Questions

  1. Why are proteins often called “body-building” foods?
    Answer: Because they are essential for the growth of new cells and the repair of damaged tissues, muscles, and organs in the body.
  2. Explain the role of water in maintaining our health.
    Answer: Water helps in transporting nutrients to cells, removing waste products, regulating body temperature, and facilitating chemical reactions in the body.
  3. What is the difference between the energy provided by carbohydrates and fats?
    Answer: Carbohydrates provide quick, immediate energy, while fats provide a more concentrated and long-term energy reserve.
  4. Why is it important to include roughage in our diet even though it does not provide energy?
    Answer: Roughage adds bulk to the food, helps in smooth bowel movements, and prevents constipation, thus keeping the digestive system healthy.
  5. Name two minerals and explain their primary function in the human body.
    Answer: 1. Calcium: It is essential for building and maintaining strong bones and teeth. 2. Iron: It is a vital component of hemoglobin, which helps red blood cells carry oxygen throughout the body.