Nutrition in Plants — Class 7 Science NCERT Solutions (Free)
Free step-by-step NCERT solutions for Class 7 Science chapter "Nutrition in Plants" — 5 important questions with detailed answers for CBSE board exam preparation.
TL;DR: Free step-by-step NCERT solutions for Class 7 Science chapter "Nutrition in Plants" — 5 important questions with detailed answers for CBSE board exam…
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NCERT Solutions for Class 7 Science — Nutrition in Plants. Step-by-step answers to all 5 textbook questions from this chapter, written for CBSE board preparation and free to use.
Nutrition in Plants — All 5 Questions Solved
Q1. पौधों को पोषण कहाँ से मिलता है?
पौधे अपना पोषण खुद तैयार करते हैं। पौधों को जड़ों के माध्यम से जल और खनिज मिलते हैं। पत्तियों से पौधों को सूर्य का प्रकाश मिलता है। वायु से कार्बन डाइऑक्साइड मिलती है। इन सबसे पौधे प्रकाश संश्लेषण द्वारा अपना भोजन बनाते हैं।
Q2. प्रकाश संश्लेषण क्या है?
प्रकाश संश्लेषण वह प्रक्रिया है जिसमें पौधे सूर्य के प्रकाश से शर्करा बनाते हैं। इसमें पानी और कार्बन डाइऑक्साइड का प्रयोग होता है। यह प्रक्रिया पत्तियों में होती है। क्लोरोफिल इस प्रक्रिया के लिए आवश्यक है। इस प्रक्रिया में ऑक्सीजन निकलती है।
Q3. पत्तियों की संरचना कैसी होती है?
पत्तियों की ऊपरी परत मोम की परत से ढकी होती है। पत्तियों में रंध्र होते हैं जिससे गैस का आदान-प्रदान होता है। पत्तियों में क्लोरोप्लास्ट होते हैं जिनमें क्लोरोफिल होता है। पत्तियों की नीचे की परत में अधिक रंध्र होते हैं। पत्तियों में शिराएँ होती हैं जो जल वहन करती हैं।
Q4. रंध्र क्या हैं और इनका कार्य क्या है?
रंध्र पत्तियों में छोटे छिद्र होते हैं। इनसे गैस का आदान-प्रदान होता है। इनसे कार्बन डाइऑक्साइड अंदर आती है और ऑक्सीजन बाहर जाती है। रंध्रों से पानी की वाष्प भी निकलती है। रंध्रों को रक्षक कोशिकाएँ घेरी होती हैं।
Q5. जड़ें पोषण अवशोषण में कैसे मदद करती हैं?
जड़ें मिट्टी से जल और खनिज अवशोषित करती हैं। जड़ों के सूक्ष्म बाल होते हैं जो सोखने का काम करते हैं। जड़ें पानी को पत्तियों तक पहुँचाती हैं। खनिज पदार्थ पूरे पौधे में वितरित होते हैं। जड़ों की संरचना सोखने के लिए विशेष है।
Nutrition in Plants — Practice MCQs with Answers
Attempt these 20 multiple-choice questions after working through the solutions above. Each carries the correct option and the reasoning behind it, so a wrong answer tells you which idea to revisit.
MCQ 1. What is the primary pigment responsible for trapping sunlight energy in plants?
- A. Chlorophyll
- B. Carotene
- C. Xanthophyll
- D. Anthocyanin
Answer: A. Chlorophyll — Chlorophyll is the green pigment present in plant leaves that absorbs sunlight energy, which is essential for the process of photosynthesis.
MCQ 2. Organisms that prepare their own food are called:
- A. Heterotrophs
- B. Saprotrophs
- C. Autotrophs
- D. Parasites
Answer: C. Autotrophs — Autotrophs are organisms, primarily plants, that can synthesize their own food using simple inorganic substances like carbon dioxide and water.
MCQ 3. Which of the following is NOT a necessary component for photosynthesis?
- A. Sunlight
- B. Carbon dioxide
- C. Oxygen
- D. Water
Answer: C. Oxygen — Photosynthesis requires sunlight, carbon dioxide, water, and chlorophyll. Oxygen is a product of photosynthesis, not a requirement.
MCQ 4. What gas is released by plants during photosynthesis?
- A. Carbon dioxide
- B. Nitrogen
- C. Oxygen
- D. Methane
Answer: C. Oxygen — During photosynthesis, plants take in carbon dioxide and release oxygen as a byproduct, which is vital for the survival of many organisms.
MCQ 5. In which part of the plant does photosynthesis primarily take place?
- A. Roots
- B. Stem
- C. Flowers
- D. Leaves
Answer: D. Leaves — Leaves are the main sites of photosynthesis in most plants, as they contain chloroplasts with chlorophyll and have stomata for gas exchange.
MCQ 6. Tiny pores on the surface of leaves through which carbon dioxide is taken in are called:
- A. Veins
- B. Stomata
- C. Sepals
- D. Petals
Answer: B. Stomata — Stomata are microscopic pores, mainly found on the lower surface of leaves, that regulate the exchange of gases like carbon dioxide and oxygen between the plant and the atmosphere.
MCQ 7. Which of the following is an example of a parasitic plant?
- A. Cactus
- B. Cuscuta (Amarbel)
- C. Sunflower
- D. Mango tree
Answer: B. Cuscuta (Amarbel) — Cuscuta, also known as Amarbel, is a non-green plant that grows on other plants (hosts) and derives its nutrition from them, making it a parasitic plant.
MCQ 8. The components of food necessary for our body are called:
- A. Fibers
- B. Roughage
- C. Nutrients
- D. Water
Answer: C. Nutrients — Nutrients are the components of food like carbohydrates, proteins, fats, vitamins, and minerals that are essential for the growth, maintenance, and repair of the body.
MCQ 9. What form of food do plants generally synthesize and store?
- A. Proteins
- B. Fats
- C. Carbohydrates (e.g., starch)
- D. Vitamins
Answer: C. Carbohydrates (e.g., starch) — Plants synthesize carbohydrates (glucose) during photosynthesis, which is then often converted into starch for storage in various parts of the plant.
MCQ 10. Insectivorous plants trap insects mainly to fulfill their requirement for which nutrient?
- A. Carbohydrates
- B. Fats
- C. Water
- D. Nitrogen
Answer: D. Nitrogen — Insectivorous plants like pitcher plants grow in soil deficient in nitrogen. They trap insects to obtain the nitrogen compounds they need for their growth.
MCQ 11. Which of the following exhibits saprotrophic mode of nutrition?
- A. Algae
- B. Mushroom
- C. Green plant
- D. Cuscuta
Answer: B. Mushroom — Mushrooms are fungi that exhibit saprotrophic nutrition, meaning they obtain nutrients from dead and decaying organic matter.
MCQ 12. Why is photosynthesis considered a vital process for life on Earth?
- A. It releases carbon dioxide
- B. It produces water
- C. It provides food and oxygen
- D. It consumes oxygen
Answer: C. It provides food and oxygen — Photosynthesis is crucial because it produces food (glucose) for plants, which forms the base of most food chains, and releases oxygen, essential for respiration by most living organisms.
MCQ 13. A relationship where two different organisms live together and benefit each other is called:
- A. Parasitism
- B. Saprotrophism
- C. Symbiosis
- D. Predation
Answer: C. Symbiosis — Symbiosis is a close and long-term biological interaction between two different biological organisms, where both benefit from the association.
MCQ 14. Lichens are an example of a symbiotic relationship between which two organisms?
- A. Fungi and bacteria
- B. Algae and fungi
- C. Plant and animal
- D. Plant and bacteria
Answer: B. Algae and fungi — Lichens represent a symbiotic association where an alga (which performs photosynthesis) and a fungus (which provides shelter and absorbs water/minerals) live together.
MCQ 15. Rhizobium bacteria help in replenishing which nutrient in the soil?
- A. Phosphorus
- B. Potassium
- C. Nitrogen
- D. Calcium
Answer: C. Nitrogen — Rhizobium bacteria live in the root nodules of leguminous plants and convert atmospheric nitrogen into usable forms for plants, thereby enriching the soil with nitrogen.
MCQ 16. How does a pitcher plant trap insects?
- A. By stinging them
- B. By producing sticky sap
- C. By having a modified leaf that forms a pitcher
- D. By releasing a strong odour
Answer: C. By having a modified leaf that forms a pitcher — The leaf of a pitcher plant is modified into a pitcher-like structure with a lid. Insects are attracted by the nectar and odour, fall into the pitcher, and are then digested.
MCQ 17. Besides chlorophyll, sunlight, and water, what other raw material is essential for photosynthesis?
- A. Oxygen
- B. Nitrogen
- C. Carbon dioxide
- D. Hydrogen
Answer: C. Carbon dioxide — Photosynthesis is the process by which green plants convert carbon dioxide and water into food using sunlight energy in the presence of chlorophyll.
MCQ 18. From where do plants primarily absorb water for photosynthesis?
- A. Air
- B. Soil
- C. Rain
- D. Other plants
Answer: B. Soil — Plants primarily absorb water from the soil through their roots, which then transports it to the leaves for photosynthesis.
MCQ 19. What test is used to confirm the presence of starch in leaves?
- A. Benedict's test
- B. Fehling's test
- C. Iodine test
- D. Litmus test
Answer: C. Iodine test — The iodine test is used to detect the presence of starch. If starch is present, iodine solution turns blue-black.
MCQ 20. Which of the following organisms are known as producers in an ecosystem?
- A. Animals
- B. Fungi
- C. Plants
- D. Bacteria
Answer: C. Plants — Plants are called producers because they can produce their own food through photosynthesis, forming the base of almost all food chains.
How to Use These Solutions
Attempt each question yourself first and only then compare with the worked answer. Marks in the CBSE board exam are awarded for the METHOD as much as the final result, so reproduce the steps rather than memorising the last line. Where a solution states a law, a formula or a definition, learn that wording — examiners look for it.
Related practice for this chapter: chapter MCQs, previous-year questions, revision notes and sample papers.