CBSE Important Questions for Class 7 Science Nutrition in Plants - 2025-26
A) Very Short Answer Questions (1 Mark)
1. Fill in the blanks:
i. The components essential for our body are called ____________.
Ans: Nutrients
ii. We obtain nutrients through ______________ .
Ans: Food
iii. Carbohydrates, _______________ and fats are important nutrients.
Ans: Proteins
iv. ____________ can make their own food from simple nutrients.
Ans: Plants/Autotrophs
v. All animals are directly or indirectly _____________ on plants for food.
Ans: Depend
2. State whether true or false. If false, correct the statement by changing the underlined word
a. Animals are the only organisms that can prepare their own food using simple substances from their surroundings.
Ans: The given statement is false. Plants are the only organisms that can prepare their own food using simple substances from the surroundings.
b. The intake of food by an organism is called nutrition.
Ans: The given statement is true.
c. Stomata absorb sunlight for photosynthesis.
Ans: The given statement is false. Chlorophyll absorbs sunlight for photosynthesis.
d. Insectivorous plants are autotrophic.
Ans: The given statement is false. Insectivorous plants are partially heterotrophic.
e. Starch on reacting with iodine solution turns brown in colour.
Ans: The given statement is false. Starch on reacting with iodine turns blue-black in color.
3. Define the following terms:
a. Nutrition
Ans: The process by which an organism receives and digests food to get the nutrients insoluble and simple forms is called Nutrition.
b. Autotrophs
Ans: The organisms which can build their own food with the help of molecules like carbon dioxide gas and water from their surroundings with the assistance of sunlight and chlorophyll are called Autotrophs.
c. Photosynthesis
Ans: The process by which organisms use sunlight to synthesise nutrients from carbon dioxide and water to create their own food is called Photosynthesis. In plants photosynthesis generally involves the green pigment called chlorophyll and generates oxygen as a secondary product.
d. Host
Ans: An organism that provides nourishment and/or shelters to some other organism is called a Host. The host supports and provides nourishment for the parasite (guest) and hence the host is negatively affected by this relationship.
e. Parasite
Ans: An organism that lives inside or on an organism of another species (its host) and which relies on the host for all the nutrients is called Parasite. The parasite is not able to survive without the host body.
B. Short Answer Questions (3 marks)
1. What are stomata? Explain their function.
Ans: The tiny pores present on the underside of the leaf surface and surrounded by guard cells are called stomata.
The functions of stomata include,
Exchanging gases by the process called diffusion for photosynthesis and respiration.
Transpiration of water i.e. the loss of excess water from the plant by evaporation of water from the upper surface of the leaf.
2. How is sunlight used by the plant for photosynthesis?
Ans:
The main energy source for photosynthesis is sunlight.
Sunlight is trapped by the green pigment chlorophyll which is present in all green parts of the plants including leaves.
The energy of the sunlight converts water and carbon dioxide into a sugar called glucose.
Glucose is used by plants for generating energy and to make other essential substances like cellulose and starch.
3. Why are some plants insectivorous? Give examples.
Ans:
Plants require nutrients like nitrogen in addition to carbohydrates for survival.
In the places where there is a lack of nutrients, especially nitrogen, some plants fulfil their nitrogen requirements by digesting insects in order to absorb the necessary nitrogen.
Examples of insectivorous plants include Venus flytrap, Utricularia, Drosera, Rafflesia, Pitcher plant, etc.
4. Explain the saprotrophic mode of nutrition with an example.
Ans:
Partial digestion of substrate outside the body and then absorbing the digested material into the body is called the saprotrophic mode of nutrition.
With the saprotrophic mode of nutrition, the body releases digestive enzymes to the substrate which causes the partial breakdown of the substrate which later on gets absorbed by the body.
Examples of organisms that follow a saprotrophic mode of nutrition include some detritivores such as fungi.
5. What is symbiosis? Explain with help of an example.
Ans: Symbiosis is a relationship that exists between two organisms living in a close physical association which is mutually beneficial for both.
In this relationship, both organisms are equally benefited and no organism is affected by this relationship. These interactions last for a long term with the survival of both species.
Examples of organisms that follow symbiosis include lichen, mycorrhiza, etc.
C) Long Answer Questions (5 marks)
1. Explain how photosynthesis occurs in plants.
Ans:
The process by which organisms use sunlight to synthesise nutrients from carbon dioxide and water to create their own food is called Photosynthesis.
In this process, organic food like starch is synthesised by inorganic molecules like water and carbon dioxide.
The main energy source which is sunlight is trapped by the green pigment.
Chlorophyll is present in all green parts of the plants including leaves.
The raw materials required are carbon dioxide and water where carbon dioxide is absorbed from the atmosphere and water is absorbed from the soil.
The energy from sunlight enables a chemical reaction that converts carbon dioxide and water into glucose and oxygen.
Glucose is used by plants for generating energy and to make other essential substances like cellulose and starch.
The overall chemical reaction during the process of photosynthesis can be represented as follows:
$6\text{C}{{\text{O}}_{\text{2}}}\text{}+\text{}12{{\text{H}}_{\text{2}}}\text{O}\xrightarrow[\text{Chlorophyll}]{\text{Light}}{{\text{C}}_{\text{6}}}{{\text{H}}_{\text{12}}}{{\text{O}}_{\text{6}}}\text{ + }6{{\text{O}}_{\text{2}}}\text{ }+\text{ }6{{\text{H}}_{\text{2}}}\text{O}$
$ \text{Carbon water glucose oxygen water} \text{dioxide} $
2. How are nutrients replenished in soil naturally? How can the nutrients be replenished artificially?
Ans:
The source of nutrients for the plants is soil.
Plants receive nutrients from the soil which leads to depletion of nutrients in the soil.
Plants are unable to use nitrogen gas directly from the atmosphere. Some bacteria convert nitrogen from the atmosphere into soluble compounds that can be used by plants.
As they live in symbiotic association with the roots of leguminous plants, the nitrogen content is replenished in the soil by their actions. Nitrogen gets replenished in the soil naturally by using leguminous plants after cereal crops in the soil.
In an artificial way, the nutrients can be replenished by using fertilisers and manure.
3. How can we demonstrate that chlorophyll is necessary for photosynthesis?
Ans:
Necessity chlorophyll can be demonstrated by carrying out an experiment on a variegated leaf.
Before the start of the experiment, the outline of the leaf is traced on a piece of paper and the green areas are marked.
To allow the process of photosynthesis, the leaf is placed in sunlight for some hours.
The leaf is then boiled in alcohol so that it gets decolorized after which the iodine solution is added to the leaf.
It can be observed in response to iodine solution the green areas of the leaf turn blue-black which indicates that the starch is present.
Thus, through this experiment, it can be observed that photosynthesis occurs in the green areas of the variegated leaf which shows that chlorophyll is necessary for photosynthesis.
4. How do plants obtain nutrients other than carbohydrates?
Ans:
Plants synthesise carbohydrates using energy from sunlight to convert carbon dioxide and water to glucose and further on into starch.
The nutrients other than carbohydrates are obtained directly from the soil.
The nitrogen content is replenished in the soil by the action of nitrogen-fixing bacteria. Nitrogen gets replenished in the soil naturally by using leguminous plants after cereal crops in the soil. Nitrogen compounds can be replenished in artificial ways by adding fertilisers and manure to the soil.
Some insectivorous plants like the pitcher plant and Venus flytrap get their nitrogen requirements fulfilled by consuming insects. In this process, the insects are trapped and digested by the plant and the nutrients are released into the body of the plant.
Some Practise Questions for Class 7 Science Chapter 1
Students here will learn a number of the essential elements in this chapter 1 of class 7. This may help them in their future grades because it sets the groundwork. Constant practice of the essential questions should help students to tackle any difficult questions in their final examinations the following are class 7th science chapter 1 important questions
How do plants obtain nutrients other than carbohydrates?
How can we demonstrate that chlorophyll is essential for photosynthesis?
How are nutrients replenished in the soil naturally?
How can nutrients be replenished in the soil artificially?
What is symbiosis in plants? give an example.
Explain the saprotrophic mode of nutrition in plants
Why are some plants insectivorous? Give an example
How is sunlight used by the plant?
What are stomata? Explain their function.
Differentiate between autotrophic and heterotrophic nutrition.
Describe the role of enzymes in the digestion of food.
What are the components of a balanced diet? Explain their importance.
Discuss the harmful effects of malnutrition on the human body.
What is the importance of water in the diet of organisms?
Explain the process of respiration in plants and animals.
How do herbivores, carnivores, and omnivores obtain nutrition?
5 Important Topics of Class 7 Science Chapter 1 You Shouldn’t Miss!
Benefits of Class 7 Science Important Questions Chapter 1 Nutrition in Plants
Clear Understanding of Concepts: These questions help in understanding how plants prepare and use food, making the topic clearer.
Effective Exam Preparation: By solving these questions, students can better prepare for exams and know what to expect.
Quick Revision Tool: These questions serve as a handy revision tool, allowing students to review important points quickly.
Practice for Better Retention: Regular practice helps retain important information about plant nutrition more effectively.
Self-Evaluation: Attempting these questions lets students check their knowledge and identify any areas that need more attention.
Confidence Building: Practising these questions can boost students' confidence as they get more familiar with the chapter’s content.
Conclusion
The Important Questions for Class 7 Science Chapter 1, Nutrition in Plants, are designed to make learning easy and effective. They cover key concepts in a simple way, helping you revise the important points and prepare confidently for your exams. You can also download Vedantu's FREE PDF, created by our subject experts, for quick study sessions anytime, anywhere. These questions provide a great way to test your understanding, improve retention, and make sure you’re well-prepared without feeling overwhelmed. Make your study time both productive and convenient with these helpful resources!
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FAQs on CBSE Important Questions for Class 7 Science Nutrition in Plants - 2025-26
1. What are the essential components required for photosynthesis, and from where do plants obtain them?
Photosynthesis is a critical process for which plants require four essential components. For exams, it's important to list them and their sources:
- Sunlight: The primary energy source, obtained directly from the sun.
- Chlorophyll: The green pigment present in the plant's leaves (in chloroplasts) that traps sunlight.
- Carbon Dioxide (CO₂): A gas taken from the atmosphere through tiny pores on the leaves called stomata.
- Water and Minerals: Absorbed from the soil by the roots and transported to the leaves through vascular tissues.
2. How can you differentiate between autotrophic and heterotrophic nutrition in plants? Provide one example for each.
This is a frequently asked question in exams. The key difference lies in how organisms obtain their food.
- Autotrophic Nutrition: In this mode, organisms produce their own food from simple inorganic substances like carbon dioxide and water, using sunlight for energy. All green plants are autotrophs. For example, a mango tree or a rose plant.
- Heterotrophic Nutrition: In this mode, organisms cannot synthesise their own food and depend on other organisms for nutrition. For example, Cuscuta (Amarbel) is a plant that depends on a host plant for its food.
3. If insectivorous plants like the pitcher plant have chlorophyll and can perform photosynthesis, why do they need to trap and consume insects?
This is a higher-order thinking (HOTS) question. While insectivorous plants do perform photosynthesis to produce carbohydrates (energy), they typically grow in soil that is very poor in essential minerals, especially nitrogen. To fulfill their nitrogen requirement for synthesising proteins, they have adapted to trap and digest insects. The insects act as a nutritional supplement, not their primary energy source.
4. Explain the saprotrophic mode of nutrition with a common example. How is it different from parasitic nutrition?
Saprotrophic nutrition is a mode where organisms obtain nutrients from dead and decaying organic matter. They secrete digestive juices onto the matter, which convert it into a solution, and then they absorb the nutrients from it. A common example is fungi, like mushrooms and bread mould.
The key difference from parasitic nutrition is that saprotrophs feed on dead organisms, while parasites derive their nutrition from a living host, often harming it in the process.
5. Why is the symbiotic relationship between Rhizobium bacteria and leguminous plants considered crucial for maintaining soil fertility?
This relationship is a classic example of symbiosis and is vital for agriculture. Leguminous plants like peas and beans cannot use the abundant atmospheric nitrogen directly. The Rhizobium bacteria, which live in the root nodules of these plants, can convert atmospheric nitrogen into a usable form (like nitrates). In return, the plant provides food and shelter to the bacteria. This natural process, called nitrogen fixation, enriches the soil with nitrogen compounds, making it more fertile and reducing the need for chemical fertilisers.
6. What types of questions, such as 1-mark, 3-mark, or 5-mark, are commonly expected from the 'Nutrition in Plants' chapter in the Class 7 Science exam?
For the CBSE Class 7 Science exam (2025-26), you can expect a mix of questions from this chapter:
- 1-Mark Questions: These are typically MCQs, fill-in-the-blanks, or one-word answers. Examples include defining terms like 'host', 'stomata', or identifying the mode of nutrition in a given plant.
- 3-Mark Questions: These often require short explanations, reasons, or differentiation. For instance, 'Give reasons why insectivorous plants trap insects' or 'Differentiate between a parasite and a saprotroph'. Drawing a simple diagram of stomata could also be a 3-mark question.
- 5-Mark Questions: These require detailed answers, often explaining an entire process. An example would be 'Explain the process of photosynthesis with a well-labelled diagram' or 'Describe the different types of heterotrophic nutrition in plants with suitable examples.'
7. Many students believe that only the leaves of a plant can perform photosynthesis. Is this statement always correct? Justify your answer.
No, this statement is not always correct. While leaves are the primary site for photosynthesis in most plants, other plant parts containing chlorophyll can also perform this process. A key example is found in desert plants like cacti. To minimise water loss through transpiration, their leaves are modified into spines. Photosynthesis is carried out by their thick, green, fleshy stems, which contain chlorophyll and are adapted for this function.
8. What is the specific role of chlorophyll and stomata in photosynthesis, and what would happen to the plant if either was absent?
Both chlorophyll and stomata have distinct and vital roles:
- Role of Chlorophyll: This green pigment, located in the chloroplasts, is responsible for trapping energy from sunlight. This captured energy is used to synthesise food from carbon dioxide and water.
- Role of Stomata: These are tiny pores on the leaf surface that facilitate gas exchange. They allow the plant to take in carbon dioxide from the atmosphere and release oxygen as a byproduct.
If a plant lacked chlorophyll, it could not capture solar energy, and photosynthesis would not occur. If it lacked stomata, it could not take in carbon dioxide, effectively halting the entire process.
