Question

A substance needed by body for growth, energy, repair and maintenance is called

• A. Carbohydrates
• B. Nutrients
• C. Calories
• D. Fatty acid

Hint:

To solve this, look for the most inclusive term. Carbohydrates and fatty acids are specific types of nutrients, and calories are a unit of energy. Therefore, "Nutrients" is the correct, overarching category.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Nutritional science studies how organisms acquire and utilize food substances to sustain life.
The body requires various chemical compounds found in food to perform metabolic functions, build tissues, produce energy, and maintain homeostasis.

Step 2: Detailed Explanation:
Let us define each of the given terms:
1. Nutrient (B):
A nutrient is any chemical substance absorbed from food that is essential for the body's growth, energy production, tissue repair, and general physiological maintenance.
Nutrients are broadly categorized into:
- Macronutrients: Required in large quantities (carbohydrates, proteins, and lipids).
- Micronutrients: Required in small quantities (vitamins and minerals).
Each nutrient class plays a specific role: proteins are primarily used for tissue repair and growth, carbohydrates and fats provide energy, and vitamins and minerals regulate metabolic pathways.
Therefore, "nutrients" is the most comprehensive and correct term.
2. Carbohydrates (A):
Carbohydrates are a specific class of macronutrient composed of carbon, hydrogen, and oxygen.
While they are the body's primary source of energy, they are not the sole substance needed for all functions like tissue repair (which requires protein).
3. Calories (C):
A calorie is a unit of measurement for energy, not a physical substance.
It measures the amount of heat energy released when food is metabolized.
4. Fatty acid (D):
Fatty acids are the building blocks of lipids (fats).
Like carbohydrates, they are a specific nutrient component rather than a comprehensive term for all essential life-sustaining substances.

Step 3: Final Answer:
A substance needed by the body for growth, energy, repair, and maintenance is called a nutrient.
Therefore, the correct option is (B).