Class 7 SCIENCE-Nutrition In Plants Full Chapter Explained

🔹 What is Nutrition? ( Class 7 SCIENCE )

Plants are one of the most important living organisms on Earth. They provide us with food, oxygen, medicines, fibres and many other useful materials. But have you ever wondered where plants get their food from? ( Class 7 SCIENCE )

Most green plants prepare their own food with the help of sunlight, carbon dioxide, water and chlorophyll. This process is called photosynthesis.

In this chapter, we will learn about:

What is nutrition?
Modes of nutrition in plants
Autotrophic nutrition
Photosynthesis
Role of chlorophyll
Raw materials required for photosynthesis
How plants obtain carbon dioxide and water
Other modes of nutrition
Parasitic plants
Insectivorous plants
Saprotrophic nutrition
Symbiotic relationship
Replenishment of nutrients in soil
RELATED POST : Healthy Body, Calm Mind | Quote of the Day – 17 August

हिंदी में परिचय ( Class 7 SCIENCE )

पौधे पृथ्वी पर जीवन के लिए बहुत महत्वपूर्ण हैं। वे हमें भोजन, ऑक्सीजन, औषधियाँ, रेशे और कई अन्य उपयोगी वस्तुएँ प्रदान करते हैं।

अधिकांश हरे पौधे अपना भोजन स्वयं बनाते हैं। वे सूर्य के प्रकाश, कार्बन डाइऑक्साइड, पानी और क्लोरोफिल की सहायता से भोजन बनाते हैं। इस प्रक्रिया को प्रकाश संश्लेषण (Photosynthesis) कहते हैं।

🌿 इस अध्याय में क्या-क्या पढ़ेंगे?

Nutrition क्या है?
Plants में Nutrition
Autotrophic Nutrition
Photosynthesis
Photosynthesis के लिए आवश्यक चीजें
Carbon Dioxide और Water पौधों तक कैसे पहुँचते हैं?
Other Modes of Nutrition
Parasitic Plants
Insectivorous Plants
Saprotrophic Nutrition
Symbiosis
Soil में Nutrients की Replenishment
Important Terms
Important Questions
MCQs
HOTS Questions
Quick Revision

🔹 2. Modes of Nutrition ( Class 7 SCIENCE )

पोषण के प्रकार

🌿 (A) Autotrophic Nutrition (स्वपोषी पोषण)

English:
Plants make their own food using sunlight, carbon dioxide, and water.

Hindi:
पौधे सूर्य के प्रकाश, कार्बन डाइऑक्साइड और जल की मदद से अपना भोजन स्वयं बनाते हैं।

👉 Plants are called Autotrophs (स्वपोषी)

(B) Heterotrophic Nutrition (परपोषी पोषण)

English:
Some organisms depend on others for food.

Hindi:
कुछ जीव अपने भोजन के लिए दूसरों पर निर्भर होते हैं। 👉 These are called Heterotrophs (परपोषी)

🔹 3. Photosynthesis (प्रकाश संश्लेषण) ( Class 7 SCIENCE )

Photosynthesis is the process by which green plants make food using sunlight, carbon dioxide, and water in the presence of chlorophyll.

Hindi:
प्रकाश संश्लेषण वह प्रक्रिया है जिसमें हरे पौधे सूर्य के प्रकाश, कार्बन डाइऑक्साइड और जल की सहायता से क्लोरोफिल की उपस्थिति में भोजन बनाते हैं।

🧪 Equation (Formula)

Carbon dioxide + Water → Glucose + Oxygen (in presence of sunlight & chlorophyll)

🌿 Steps of Photosynthesis

English:

Leaves take in carbon dioxide
Roots absorb water
Sunlight is trapped by chlorophyll
Food (glucose) is prepared
Oxygen is released

Hindi:

पत्तियाँ कार्बन डाइऑक्साइड लेती हैं
जड़ें पानी अवशोषित करती हैं
क्लोरोफिल सूर्य के प्रकाश को पकड़ता है
भोजन (ग्लूकोज) बनता है
ऑक्सीजन बाहर निकलती है

🔹 4. Role of Leaves (पत्तियों की भूमिका) ( Class 7 SCIENCE )

English:

Leaves are the food factory of plants
They contain chlorophyll

Hindi:

पत्तियाँ पौधों का भोजन बनाने का कारखाना हैं
इनमें क्लोरोफिल होता है

🔹 5. Stomata (रंध्र) ( Class 7 SCIENCE )

English:
Tiny pores on leaves that help in gas exchange.

Hindi:
पत्तियों पर छोटे-छोटे छिद्र जो गैसों का आदान-प्रदान करते हैं।

Other Modes of Nutrition in Plants

पौधों में अन्य पोषण के प्रकार

🪴 (A) Parasite (परजीवी)

English:
Plants that take food from other plants.

Example: Cuscuta (Amarbel)

Hindi:
दूसरे पौधों से भोजन लेने वाले पौधे।

🍄 (B) Saprotrophs (मृतजीवी)

English:
Organisms that feed on dead matter.

Example: Fungi

Hindi:
मरे हुए पदार्थों से भोजन लेने वाले जीव।

🐜 (C) Insectivorous Plants (कीटभक्षी पौधे)

English:
Plants that eat insects.

Example: Pitcher plant

Hindi:
कीड़े खाने वाले पौधे।

🤝 (D) Symbiosis (सहजीवन)

English:
Two organisms live together and help each other.

Example: Lichen

Hindi:
दो जीव साथ रहते हैं और एक-दूसरे की मदद करते हैं।

🔹 7. Replenishment of Nutrients in Soil

मिट्टी में पोषक तत्वों की पूर्ति

English:

By fertilizers and manure
By nitrogen-fixing bacteria (Rhizobium)

Hindi:

खाद और उर्वरक द्वारा

नाइट्रोजन स्थिरीकरण करने वाले जीवाणु (राइजोबियम

7. Raw Materials Required for Photosynthesis

Plants need four major things for photosynthesis:

Requirement	Source/Role
Sunlight	Provides energy
Chlorophyll	Absorbs sunlight
Carbon dioxide	Obtained from air
Water	Absorbed from soil

हिंदी में

आवश्यक चीज	स्रोत/कार्य
सूर्य का प्रकाश	ऊर्जा प्रदान करता है
क्लोरोफिल	सूर्य के प्रकाश को अवशोषित करता है
कार्बन डाइऑक्साइड	वायु से प्राप्त होती है
पानी	मिट्टी से प्राप्त होता है

8. How Do Plants Obtain Carbon Dioxide?

Plants obtain carbon dioxide from the atmosphere.

Leaves have tiny pores called stomata through which gases enter and leave the leaf.

हिंदी में

पौधे वायुमंडल से कार्बन डाइऑक्साइड प्राप्त करते हैं।

पत्तियों की सतह पर बहुत छोटे-छोटे छिद्र होते हैं जिन्हें रंध्र (Stomata) कहा जाता है।

इन रंध्रों के माध्यम से गैसों का आदान-प्रदान होता है।

Important Point ( Class 7 SCIENCE )

Stomata = Tiny pores present mainly on leaves for exchange of gases.

रंध्र = पत्तियों पर पाए जाने वाले छोटे छिद्र, जिनके माध्यम से गैसों का आदान-प्रदान होता है।

9. How Do Plants Obtain Water? ( Class 7 SCIENCE )

Plants absorb water from the soil through their roots.

The roots contain tiny structures called root hairs, which help in absorbing water and minerals from the soil.

हिंदी में ( Class 7 SCIENCE )

पौधे अपनी जड़ों के द्वारा मिट्टी से पानी और खनिज लवण प्राप्त करते हैं।

जड़ों पर छोटे-छोटे मूल रोम (Root Hairs) होते हैं, जो मिट्टी से पानी और खनिजों के अवशोषण में सहायता करते हैं।

The absorbed water is transported to different parts of the plant through conducting tissues.

10. Role of Sunlight in Photosynthesis

Sunlight provides the energy required for photosynthesis.

Without sufficient light, green plants cannot perform photosynthesis effectively.

हिंदी में ( Class 7 SCIENCE )

सूर्य का प्रकाश प्रकाश संश्लेषण के लिए आवश्यक ऊर्जा प्रदान करता है।

पर्याप्त प्रकाश के बिना हरे पौधे प्रभावी रूप से प्रकाश संश्लेषण नहीं कर सकते।

11. What Happens to the Food Prepared by Plants?

The glucose prepared during photosynthesis can be used by the plant for:

Energy
Growth
Development
Repair
Formation of other substances

Some of the food is stored as starch.

हिंदी में ( Class 7 SCIENCE )

प्रकाश संश्लेषण के दौरान बना ग्लूकोज़ पौधे के लिए:

ऊर्जा
वृद्धि
विकास
मरम्मत
अन्य पदार्थों के निर्माण

में उपयोग होता है।

अतिरिक्त भोजन स्टार्च (Starch) के रूप में संचित किया जा सकता है।

12. Test for Starch in a Leaf ( Class 7 SCIENCE )

A common experiment can be used to show the presence of starch in a leaf.

Basic idea

If a leaf contains starch, it gives a blue-black colour when tested with iodine solution.

हिंदी में ( Class 7 SCIENCE )

यदि पत्ती में स्टार्च उपस्थित है, तो आयोडीन विलयन डालने पर वह नीला-काला (Blue-Black) रंग दिखाती है।

Why is this test important?

It helps us understand that food produced during photosynthesis can be stored as starch.

13. Other Modes of Nutrition in Plants

Not all plants obtain nutrition in exactly the same way.

Some plants depend partly or completely on other organisms.

Such modes are called heterotrophic modes of nutrition.

Important examples include:

Parasitic nutrition
Insectivorous nutrition
Saprotrophic nutrition
Symbiotic nutrition

14. Parasitic Plants ( Class 7 SCIENCE )

A parasitic plant obtains food from another living plant called the host.

One well-known example is Cuscuta.

Cuscuta is commonly called Amarbel.

It is yellowish and does not have enough chlorophyll to prepare sufficient food by itself.

It obtains nutrients from the host plant.

हिंदी में ( Class 7 SCIENCE )

परजीवी पौधे (Parasitic Plants) अपना भोजन किसी दूसरे जीवित पौधे से प्राप्त करते हैं। जिस पौधे से भोजन प्राप्त किया जाता है उसे Host यानी पोषक पौधा कहते हैं।

Cuscuta (अमरबेल) इसका एक प्रमुख उदाहरण है।

यह दूसरे पौधों पर लिपटकर उनसे पोषक पदार्थ प्राप्त करती है।

Key Terms

Parasite = परजीवी
Host = पोषक/आश्रयदाता

15. Insectivorous Plants ( Class 7 SCIENCE )

Some green plants obtain additional nutrients by trapping and digesting insects.

These plants are called insectivorous plants.

Examples:

Pitcher plant
Venus flytrap
Sundew

हिंदी में

कुछ हरे पौधे कीटों को पकड़कर उनसे अतिरिक्त पोषक पदार्थ प्राप्त करते हैं। ऐसे पौधों को कीटभक्षी पौधे (Insectivorous Plants) कहते हैं।

उदाहरण:

Pitcher Plant
Venus Flytrap
Sundew

Why Do Insectivorous Plants Eat Insects?

Insectivorous plants are generally found in soils that are poor in certain nutrients, especially nitrogen.

They trap insects to obtain additional nutrients.

हिंदी में ( Class 7 SCIENCE )

कीटभक्षी पौधे अक्सर ऐसी मिट्टी में पाए जाते हैं जिसमें कुछ आवश्यक पोषक तत्व, विशेषकर नाइट्रोजन, कम होते हैं।

इसलिए वे कीटों को पकड़कर अतिरिक्त पोषक पदार्थ प्राप्त करते हैं।

Important

The main food-making process in green insectivorous plants is still photosynthesis.

Insects mainly provide additional nutrients.

16. Saprotrophic Nutrition

Some organisms obtain nutrients from dead and decaying organic matter.

This mode of nutrition is called saprotrophic nutrition.

Examples include:

Mushroom
Many fungi

हिंदी में

कुछ जीव मृत एवं सड़े-गले जैविक पदार्थों से पोषक तत्व प्राप्त करते हैं।

इस प्रकार के पोषण को मृतजीवी पोषण (Saprotrophic Nutrition) कहते हैं।

Mushrooms और कई fungi इसके उदाहरण हैं।

How does it work?

Saprotrophs release digestive substances onto the dead matter. The complex substances are broken down into simpler substances, which are then absorbed.

हिंदी में ( Class 7 SCIENCE )

मृतजीवी जीव मृत पदार्थों पर पाचक पदार्थ छोड़ते हैं। ये जटिल पदार्थों को सरल पदार्थों में बदल देते हैं और फिर उन्हें अवशोषित कर लेते हैं।

17. Symbiotic Relationship

Sometimes two different organisms live together and both benefit from the relationship.

This is called symbiosis.

A common example is lichen.

Lichen consists of:

Algae
Fungus

The algae prepare food by photosynthesis, while the fungus provides water, minerals and shelter.

हिंदी में ( Class 7 SCIENCE )

जब दो अलग-अलग जीव साथ रहते हैं और दोनों को लाभ होता है, तो इसे सहजीवी संबंध (Symbiosis) कहते हैं।

Lichen इसका एक अच्छा उदाहरण है।

Lichen में:

Algae (शैवाल)
Fungus (कवक)

होते हैं।

शैवाल प्रकाश संश्लेषण द्वारा भोजन बनाता है, जबकि कवक पानी, खनिज और आश्रय प्रदान करता है।

18. Replenishment of Nutrients in the Soil

Plants continuously absorb nutrients from the soil.

Therefore, the amount of nutrients in soil may decrease over time.

Farmers add manure and fertilizers to increase nutrients in the soil.

Another important natural process is carried out by Rhizobium bacteria.

हिंदी में

पौधे लगातार मिट्टी से पोषक तत्व प्राप्त करते हैं। इसलिए समय के साथ मिट्टी में पोषक तत्वों की मात्रा कम हो सकती है।

किसान मिट्टी की उर्वरता बनाए रखने के लिए खाद और उर्वरक का उपयोग करते हैं।

इसके अलावा Rhizobium bacteria भी महत्वपूर्ण भूमिका निभाते हैं।

19. Role of Rhizobium Bacteria

Rhizobium bacteria are commonly found in the root nodules of leguminous plants such as:

Pea
Gram
Bean
Groundnut

Rhizobium helps convert atmospheric nitrogen into forms that plants can use.

हिंदी में

Rhizobium जीवाणु दलहनी पौधों की जड़ों में बनी Root Nodules (जड़ ग्रंथियों) में पाए जाते हैं।

उदाहरण:

मटर
चना
सेम
मूंगफली

Rhizobium वायुमंडलीय नाइट्रोजन को ऐसे रूप में बदलने में सहायता करता है जिसे पौधे उपयोग कर सकें।

Important

This process helps improve soil fertility.

⭐ Important Differences ( Class 7 SCIENCE )

Autotrophic vs Heterotrophic Nutrition

Autotrophic Nutrition	Heterotrophic Nutrition
Organism prepares its own food	Organism depends on other sources
Common in green plants	Seen in parasites, saprotrophs etc.
Photosynthesis is usually involved	Food is obtained from other organisms/materials
Example: Green plants	Example: Cuscuta, fungi

Parasite vs Saprotroph ( Class 7 SCIENCE )

Parasite	Saprotroph
Obtains nutrition from a living host	Obtains nutrition from dead and decaying matter
Host is living	Source is dead/decaying material
Example: Cuscuta	Example: Mushroom

📚 Important Terms ( Class 7 SCIENCE )

Term	Meaning
Nutrition	Process of obtaining and using food
Autotroph	Organism that makes its own food
Heterotroph	Organism that depends on other sources for food
Photosynthesis	Process of food preparation by green plants
Chlorophyll	Green pigment that absorbs sunlight
Stomata	Tiny pores on leaves
Parasite	Organism obtaining food from a living host
Host	Organism from which a parasite obtains food
Saprotroph	Organism obtaining nutrients from dead matter
Symbiosis	Living together with mutual benefit
Rhizobium	Nitrogen-fixing bacterium associated with legume roots

📗 Important Questions ( Class 7 SCIENCE )

Q1. What is photosynthesis?

Hindi: प्रकाश संश्लेषण क्या है?
👉 (Definition above)

Q2. Why are leaves called food factories?

English: Because they prepare food.
Hindi: क्योंकि वे भोजन बनाती हैं।

Q3. What is stomata?

👉 Small pores on leaves

30 MCQs with Answers ( Class 7 SCIENCE )

1. The process by which green plants prepare their own food is called:

A) Respiration
B) Digestion
C) Photosynthesis
D) Transpiration

Answer: C) Photosynthesis

2. Which pigment is essential for photosynthesis?

A) Hemoglobin
B) Chlorophyll
C) Melanin
D) Keratin

Answer: B) Chlorophyll

3. Which gas is taken in by plants during photosynthesis?

A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Hydrogen

Answer: C) Carbon dioxide

4. Plants are called autotrophs because they:

A) Eat other organisms
B) Make their own food
C) Live in water
D) Reproduce rapidly

Answer: B) Make their own food

5. The food prepared by plants is mainly stored as:

A) Protein
B) Vitamins
C) Starch
D) Minerals

Answer: C) Starch

6. Tiny pores on leaves are called:

A) Veins
B) Roots
C) Stomata
D) Petals

Answer: C) Stomata

7. Water is absorbed from the soil by:

A) Leaves
B) Flowers
C) Root hairs
D) Stem

Answer: C) Root hairs

8. Which of the following is a parasite?

A) Mushroom
B) Cuscuta
C) Rose
D) Mango

Answer: B) Cuscuta

9. Cuscuta is commonly known as:

A) Dodder
B) Lotus
C) Moss
D) Fern

Answer: A) Dodder

10. Which plant traps insects?

A) Neem
B) Pitcher Plant
C) Banyan
D) Sunflower

Answer: B) Pitcher Plant

11. Mushroom obtains food by:

A) Photosynthesis
B) Saprotrophic nutrition
C) Parasitic nutrition
D) Insectivorous nutrition

Answer: B) Saprotrophic nutrition

12. The leaves of plants appear green due to:

A) Carotene
B) Chlorophyll
C) Starch
D) Glucose

Answer: B) Chlorophyll

13. Oxygen released during photosynthesis comes out through:

A) Roots
B) Flowers
C) Stomata
D) Fruits

Answer: C) Stomata

14. Which of the following is NOT required for photosynthesis?

A) Sunlight
B) Carbon dioxide
C) Water
D) Oxygen

Answer: D) Oxygen

15. Rhizobium bacteria live in:

A) Leaves
B) Flowers
C) Root nodules of legumes
D) Stem

Answer: C) Root nodules of legumes

16. Rhizobium helps plants by:

A) Producing oxygen
B) Fixing nitrogen
C) Absorbing water
D) Making flowers

Answer: B) Fixing nitrogen

17. Lichens are an example of:

A) Parasitism
B) Saprotrophism
C) Symbiosis
D) Insectivory

Answer: C) Symbiosis

18. Which organism is a saprotroph?

A) Cuscuta
B) Mushroom
C) Pitcher Plant
D) Rose Plant

Answer: B) Mushroom

19. The raw material for photosynthesis obtained from air is:

A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Hydrogen

Answer: C) Carbon dioxide

20. Plants convert solar energy into:

A) Mechanical energy
B) Heat energy
C) Chemical energy
D) Sound energy

Answer: C) Chemical energy

21. Which part of the plant mainly performs photosynthesis?

A) Root
B) Stem
C) Leaf
D) Flower

Answer: C) Leaf

22. The mode of nutrition in green plants is:

A) Heterotrophic
B) Autotrophic
C) Saprotrophic
D) Parasitic

Answer: B) Autotrophic

23. Which nutrient is added to soil by Rhizobium?

A) Potassium
B) Calcium
C) Nitrogen
D) Iron

Answer: C) Nitrogen

24. Insectivorous plants trap insects mainly to obtain:

A) Water
B) Nitrogen
C) Oxygen
D) Sugar

Answer: B) Nitrogen

25. The product of photosynthesis is:

A) Glucose
B) Carbon dioxide
C) Nitrogen
D) Minerals

Answer: A) Glucose

26. Which of the following is a leguminous plant?

A) Pea
B) Mango
C) Rose
D) Coconut

Answer: A) Pea

27. Symbiosis means:

A) Competition between organisms
B) One organism harming another
C) Living together for mutual benefit
D) Living alone

Answer: C) Living together for mutual benefit

28. The test used to detect starch is:

A) Iodine Test
B) Litmus Test
C) Benedict Test
D) Flame Test

Answer: A) Iodine Test

29. Which structure transports water from roots to leaves?

A) Xylem
B) Phloem
C) Stomata
D) Petiole

Answer: A) Xylem

30. Photosynthesis helps maintain the balance of:

A) Oxygen and Carbon Dioxide
B) Nitrogen and Hydrogen
C) Calcium and Iron
D) Potassium and Magnesium

Answer: A) Oxygen and Carbon Dioxide

HOTS (Higher Order Thinking Skills) Questions

1.

A plant is kept in complete darkness for a week. What changes would you expect in its food production and why?

Answer: The plant will not be able to perform photosynthesis and therefore cannot produce food.

2.

Why do insectivorous plants trap insects even though they can perform photosynthesis?

Answer: They grow in nitrogen-deficient soils and obtain nitrogen from insects.

3.

How would life on Earth be affected if chlorophyll disappeared from all plants?

Answer: Photosynthesis would stop, food chains would collapse, and oxygen levels would decrease drastically.

4.

Explain why mushrooms are not considered producers.

Answer: They cannot make their own food and depend on dead and decaying matter.

5.

A farmer grows leguminous crops before wheat. How does this help the soil?

Answer: Rhizobium bacteria in legume roots enrich the soil with nitrogen.

6.

Can a plant survive if its stomata are permanently closed? Give reasons.

Answer: No. Gas exchange and transpiration would stop, affecting photosynthesis and plant growth.

7.

Why is photosynthesis considered the foundation of almost all food chains?

Answer: Plants are primary producers and provide food directly or indirectly to all organisms.

8.

If carbon dioxide concentration in the atmosphere decreases sharply, what will happen to plants?

Answer: Photosynthesis rate will decrease, reducing food production and plant growth.

9.

How are lichens a perfect example of cooperation in nature?

Answer: Algae prepare food while fungi provide shelter, water, and minerals. Both benefit from the association.

10.

A yellow-colored leaf and a green-colored leaf are exposed to sunlight. Which one will produce more food and why?

Answer: The green leaf will produce more food because it contains more chlorophyll for photosynthesis.

Conclusion (English)

Nutrition in Plants is one of the most important chapters in Class 7 Science because it explains how plants prepare their own food through the process of photosynthesis. Green plants are called autotrophs as they produce food using sunlight, water, carbon dioxide, and chlorophyll. We also learned about different modes of nutrition such as parasitic, saprotrophic, insectivorous, and symbiotic nutrition. Understanding this chapter helps students appreciate the vital role of plants in maintaining life on Earth by providing food and oxygen. A strong understanding of this topic is essential for school exams, competitive tests, and future science studies.

निष्कर्ष (Hindi)

पौधों में पोषण (Nutrition in Plants) कक्षा 7 विज्ञान का एक महत्वपूर्ण अध्याय है, जो हमें यह समझाता है कि पौधे प्रकाश संश्लेषण (Photosynthesis) की प्रक्रिया द्वारा अपना भोजन स्वयं कैसे बनाते हैं। हरे पौधों को स्वपोषी (Autotrophs) कहा जाता है क्योंकि वे सूर्य के प्रकाश, जल, कार्बन डाइऑक्साइड और क्लोरोफिल की सहायता से भोजन तैयार करते हैं। इस अध्याय में हमने परजीवी (Parasitic), मृतोपजीवी (Saprotrophic), कीटभक्षी (Insectivorous) तथा सहजीवी (Symbiotic) पोषण के बारे में भी अध्ययन किया। यह अध्याय हमें प्रकृति में पौधों के महत्व तथा पृथ्वी पर जीवन बनाए रखने में उनकी भूमिका को समझने में सहायता करता है। बोर्ड परीक्षाओं, प्रतियोगी परीक्षाओं और विज्ञान की आगे की पढ़ाई के लिए इस अध्याय की अच्छी समझ अत्यंत आवश्यक है।