Class 9th Biology Unit 08 NUTRITION Question And Answer

Short And Simple Question And Answer

Q.1. Define Nutrition and Nutrients?

Ans: Nutrition refers to the process by which organisms acquire and utilize food for energy, growth, and maintenance. Nutrients are substances essential for sustaining life and proper bodily function, including carbohydrates, proteins, fats, vitamins, and minerals.

Q.2. Describe types of organisms on the basis of nutrition?

Ans: Organisms are categorized based on their nutritional intake: autotrophs (produce their own food, like plants), heterotrophs (rely on external sources for food, like animals), and mixotrophs (capable of both autotrophic and heterotrophic nutrition, like certain bacteria).

Q.3. How do plants get their food? Explain briefly?

Ans: Plants primarily use photosynthesis to create their food. They absorb water and minerals from the soil and carbon dioxide from the air. Through photosynthesis, using sunlight, they convert these substances into glucose (food) and oxygen.

Q.4. Define macronutrients and micronutrients. Explain mineral requirements of plants in detail?

Ans: Macronutrients are nutrients required in larger quantities by plants, such as nitrogen, phosphorus, and potassium. Micronutrients are needed in smaller amounts, like iron, manganese, and zinc. Plants require minerals for various functions like growth, enzyme activity, and maintaining cellular structure.

Q.5. What is the role of nitrogen and magnesium in plant growth?

Ans: Nitrogen is crucial for plant growth as it aids in chlorophyll production, which is vital for photosynthesis. Magnesium is an essential component of chlorophyll, contributing to the green pigment in plants and playing a key role in photosynthesis.

Q.6. How are inorganic and organic fertilizers important in agriculture?

Ans: Inorganic fertilizers provide specific nutrients to plants in readily available forms. Organic fertilizers, derived from natural sources, improve soil structure and nutrient retention over time. Both types are essential in maintaining soil fertility and ensuring optimal plant growth in agriculture.

Q.7. Discuss the hazards of the environment related to fertilizer use?

Ans: Fertilizer use can lead to water pollution, soil degradation, air pollution, eutrophication, and biodiversity loss, affecting aquatic life, soil quality, air quality, and ecosystems.

Q.8. Describe the sources, energy values, and functions of carbohydrates, proteins, and fats in detail?

Ans: Carbohydrates (from grains, fruits) provide energy; proteins (from meat, beans) build tissues; fats (from oils, nuts) store energy, insulate, and aid in nutrient absorption.

Q.9. What are minerals? Discuss their roles in the human body.

Ans: Minerals are essential nutrients (like calcium, iron) crucial for body functions: bone health, oxygen transport, nerve signaling, and enzyme reactions.

Q.12. Why are water and dietary fibers considered important in our diets?

Ans: Water hydrates, aids digestion, and regulates body temperature. Dietary fibers (from fruits, vegetables) aid digestion, prevent constipation, and lower cholesterol.

Q.13. What is a balanced diet? How would you relate it to age, sex, and activity?

Ans: A balanced diet contains essential nutrients in appropriate proportions. Requirements vary based on age, sex, and activity level; e.g., athletes need more protein.

Q.14. Define malnutrition. Describe its importance and forms?

Ans: Malnutrition is a condition due to inadequate or excessive nutrient intake. Its importance lies in affecting growth, immunity, and overall health. Forms include undernutrition, overnutrition, and micronutrient deficiencies.

Q.15. Describe effects of Malnutrition?

Ans: Malnutrition can lead to stunted growth, weakened immunity, cognitive impairments, organ damage, and increased susceptibility to diseases.

Q.16. Describe famine as the major cause of malnutrition?

Ans: Famine, caused by food shortages, leads to widespread hunger and undernutrition in populations, resulting in malnutrition-related health issues.

Q.17. Describe digestion and its phases?

Ans: Digestion is the breakdown of food into absorbable nutrients. Phases include mechanical (chewing) and chemical (enzymatic breakdown) digestion in the mouth, stomach, and intestines.

Q.18. Explain various parts of the digestive system and the process of digestion and absorption in detail?

Ans: The digestive system comprises the mouth, esophagus, stomach, intestines, and associated organs. Digestion involves enzymes breaking down food into nutrients, which are then absorbed through the intestines into the bloodstream for use by the body.