Imp Questions For All Chapters – General Science Class 7
Nutrition in Living Organisms
Short Questions
1. What is malnutrition?
→ Malnutrition is a condition caused by a lack of proper nutrients in the diet.
2. What are the two types of nutrients?
→ Macro-nutrients (carbohydrates, proteins, fats) and micro-nutrients (vitamins, minerals).
3. What is photosynthesis?
→ Photosynthesis is the process by which plants make their own food using sunlight, carbon dioxide, and water.
4. Which part of the plant carries out photosynthesis?
→ Mainly leaves, but sometimes green stems also perform photosynthesis.
5. What are autotrophic plants?
→ Plants that make their own food, like mango and wheat, are autotrophic plants.
6. What are heterotrophic plants?
→ Plants that depend on other organisms for food, like cuscuta and pitcher plants.
7. What are stomata?
→ Stomata are small openings on leaves that allow gases to enter and exit.
8. What is the function of chlorophyll?
→ Chlorophyll absorbs sunlight and helps in photosynthesis.
9. What are parasitic plants?
→ Plants that take food from other plants, like cuscuta and loranthus.
10. What is symbiotic nutrition?
→ When two organisms help each other for survival, like lichen (algae + fungi).
11. Which micro-organisms help in nitrogen fixation in soil?
→ Rhizobium and Azotobacter convert nitrogen into nitrates for plants.
12. What is saprophytic nutrition?
→ Some plants absorb nutrients from dead and decaying matter, like mushrooms.
13. What are insectivorous plants?
→ Plants that trap and eat insects, like Venus flytrap and pitcher plant.
14. What is the role of xylem in plants?
→ Xylem transports water and minerals from roots to leaves.
15. What is the role of phloem in plants?
→ Phloem transports food (glucose) from leaves to other parts of the plant.
Long Questions
1. Why do living organisms need nutrition?
→ Nutrition gives energy for daily activities, helps in growth, repair of body cells, and protects from diseases.
2. Explain the process of photosynthesis in plants.
→ Plants use sunlight, water, and carbon dioxide to make food in leaves with the help of chlorophyll, releasing oxygen as a byproduct.
3. What are parasitic plants? Give examples.
→ Parasitic plants take food from other plants; cuscuta is fully parasitic, while loranthus is a partial parasite.
4. What are the different steps of nutrition in animals?
→ The steps are ingestion (eating), digestion (breaking food), absorption (nutrients enter blood), assimilation (energy use), and egestion (waste removal).
5. How do unicellular organisms obtain nutrition?
→ Amoeba uses pseudopodia (false feet) to surround food, digest it inside, and expel waste through its outer membrane.
6. Why are insectivorous plants brightly colored?
→ Their bright colors attract insects for food, as they grow in nitrogen-poor soil and need extra nutrients.
7. Why do butterflies have a long tube-like proboscis?
→ A butterfly’s proboscis acts like a straw, helping it suck nectar from flowers easily.
8. What is the importance of nitrogen for plants?
→ Nitrogen is needed for protein formation and chlorophyll production, helping in growth and photosynthesis.
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