# NCERT Solutions for Class 7 Science

## NCERT Solutions for Class 7 Science Chapter 1 - Nutrition in Plants

NCERT Class 7 Science Chapter 1 is based on different modes of nutrition in plants. Experts at Vedantu have made NCERT Solutions for Class 7 Science Chapter 1 PDF format available for students that will help them build a strong base on plant nutrition. The questions are selected covering topics of Science Class 7 Chapter 1 in a precise manner. Provided solutions are equally effective for a student as it's accessible from anywhere. You can also download NCERT Solutions for Class 7 Maths to help you to revise complete syllabus and score more marks in your examinations.

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NCERT Class 7 Science Chapter 1 is visually appealing as it exposes you to the world of plants. The curriculum includes a range of tasks that will encourage kids to love studying. You will like studying this Chapter since the curriculum introduces you to new vocabulary and concepts.

In the Class 7 Nourishment in Plants Chapter, students will learn about many new topics linked to plants and how they obtain nutrition for themselves. They will also learn about photosynthesis, chlorophyll, stomata, etc. Plants with different forms of sustenance, such as insectivorous plants are also discussed in this chapter.

This chapter will cover the fundamentals of plant nutrition and how plants create their food, but reading it attentively will help students comprehend botany principles at a deeper level. As a result, it is strongly advised that students should make notes so that they may revise them while preparing this chapter for the exam.

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## Access NCERT Solutions for Science Chapter 1– Nutrition in Plants

Q1.Why Do Organisms Need To Take Food?

Ans: Organism needs food to:-

(i) Survive.

(ii) Growth.

(iii)Gain Energy.

(iv) Damage repair.

(v) Maintain bodily functions.

(vi) Other activities.

Q2. Distinguish Between a Parasite and Saprophyte.

Ans: Differences between Parasite and saprophytes are as follows:

 Parasite Saprophyte Parasites are living entities that rely on their host to survive. Humans, animals, and plants all have parasites.  They belong to the category of eukaryotic organisms.Examples- Tapeworm, barnacles. Saprophytes are organisms that feed on decomposing or dead substances. Saprophytes are found solely in plants and animals.Saprophytes can be eukaryotic or prokaryotic.Examples- Mushrooms, molds.

Q3. How Would You Test the Presence of Starch in Leaves?

Ans: When starch reacts with an iodine solution, it takes on a characteristic dark blue color.  If a few drops of iodine solution are applied to a leaf and a dark blue color develops, the existence of starch in the leaf is confirmed.

Q4. Give a Brief Description of the Process of Synthesis of Food in Green Plants.

Ans: In green plants, the synthesis of food occurs by a process called photosynthesis. During this process, chlorophyll in the cells of the leaves uses carbon dioxide and water to synthesize carbohydrates in the presence of sunlight. The process can be represented by an equation:

$Carbon\:dioxide\:+\:\:Water\:\xrightarrow[Chlorophyll]{Sunlight}\:Carbohydrates\:+Oxygen$

During this process, oxygen is released, and the carbohydrates generated are stored as starch.

Q5. Show with the help of a sketch that the plants are the ultimate source of food.

Ans:

6. Fill in the blanks:

1. Green plants are called ----------- since they synthesize their own food.

Ans: Green plants are called autotrophs since they synthesize their own food.

1. The Food Synthesized by the Plants is Stored as ---------------.

Ans: The food synthesized by the plants is stored as starch.

1. In Photosynthesis, Solar Energy is Captured by the Pigment Called------------.

Ans: In photosynthesis, solar energy is captured by the pigment called chlorophyll.

1. During photosynthesis plants take in ------------- and release

-------------.

Ans: During photosynthesis, plants take in carbon dioxide and release oxygen.

Q7. Name the following:

1. A Parasitic Plant With a Yellow, Slender, and Tubular Stem.

Ans: Cuscuta- The Cuscuta plant is classified as a parasite since it lacks chlorophyll and feeds on the host. The host loses vital nutrients as a result of this process.

1. A Plant That Has Both Autotrophic and Heterotrophic Modes of Nutrition.

Ans: Pitcher plant - The pitcher plant is an autotrophic plant that performs photosynthesis, but it also has a partly heterotrophic method of nutrition because it grows in nitrogen-deficient soil.

1. The Pores Through Which Leaves Exchange Gases.

Ans: Stomata- Gases such as carbon dioxide, water vapor, and oxygen can diffuse into and out of the plant's interior tissues through stomata.

### Q8. Tick the Correct Answer:

1. Amarbel is an Example of:

(i)Autotroph

(ii) Parasite

(iii) Saprophyte

(iv) Host

Ans: (ii) Parasite-

Cuscuta or Dodder are other names for Amarbel. A parasite is an organism that grows on the body of another organism and feeds on its nutrition.

1. The Plant Which Traps and Feeds on Insects is:

(i) Cuscuta

(ii) China rose

(iii) Pitcher plant

(iv) Rose

Ans: (iii) Pitcher plant

The pitcher plant is a type of plant with trapping and digesting leaves. Medicine is made from the leaf and root.

Q9. Match the item in given column I with those in column II.

Column I                                                                           Column II

1. Chlorophyll                                                                      (a) Bacteria

2. Nitrogen                                                                           (b) Heterotrophs

3. Amarbel                                                                            (c) Pitcher plant

4. Animals                                                                             (d) Leaf

5. Insects                                                                               (e) Parasite

Ans: (i)-(d); (ii)-(a); (iii)-(e); (iv)-(b); (v)-(c)

Q10. Mark “T” if the statement is true and “F” if it is false:

1. Carbon dioxide is released during photosynthesis. (T/F)

Ans: False- Oxygen is released during photosynthesis.

1. Plants that synthesize their food themselves are called saprotrophs. (T/F)

Ans: False- Plants which synthesize their food themselves are called autotrophs.

1.  The product of photosynthesis is not a protein. (T/F)

Ans: True- The product of photosynthesis is not a protein.

1.  Solar energy is converted into chemical energy during photosynthesis. (T/F)

Ans: True- Solar energy is converted into chemical energy during photosynthesis.

Q11. Choose the Correct Option From the Following:

Which part of the plant gets carbon dioxide from the air for photosynthesis?

1. Root hair

2. Stomata

3. Leaf veins

4. Sepals

Ans: (b) Stomata gets carbon dioxide from the air for photosynthesis.

Q12. Choose the Correct Option From the Following:

Plants take carbon dioxide from the atmosphere mainly through their:

1. Roots

2. Stem

3. Flowers

4. Leaves

Ans: (d) Plants take carbon dioxide from the atmosphere mainly through their leaves.

### NCERT Solutions for Class 7 Science- Free PDF Download

Nutrition in plants Class 7 NCERT is a good conceptual chapter for the students of Class 7. The Official website has all Class 7 Science Chapter 1 Solution available in PDF format for students to get easy access. These solutions have the entire Ch 1 Science for Class 7 covered and will help students to score better marks in Science exams.

### Important Topics Covered in Chapter 1 of Class 7 Science- Nutrition in Plants

 Nutrition in Plants Mode of Nutrition in Plants Photosynthesis – a food-making process in Plants The alternative mode of nutrition in Plants Saprophytes Nutrient replenishment in the soil

### 1.1 Mode of Nutrition in Plants

Among all living beings, plants are the only ones who can make their own food. They prepare their food from sunlight, minerals, water and carbon dioxide that exist in the surrounding. The nutrients help the plant to grow, build itself and repair damaged body parts. The nutrients also provide the required energy to perform vital life processes. The mode is nutrition by which an organism takes nutrients from its surroundings and utilizes it in its body.

There are two modes of nutrition- autotrophic and heterotrophic nutrition mode. Autotrophic nutrition mode enables the organisms to make their food from simpler substances from the surrounding. For example, plants are autotrophs. Heterotrophic nutrition mode allows the organism to derive their nutrients from other animals. For example, all animals are heterotroph.

Since plants are autotrophs, the next questions that will come to you are how do plants make their food.

### 1.2 Photosynthesis- Food Making Process in Plants

You must have learned that leaves are considered as food factories in plants. They synthesize the food for all parts of the plant. The different body parts transport different raw materials to the parts of the leaves. The roots absorb water and minerals from the soil and send it to leaves through vessels that run all over the root, stem and leaves. Tiny pores on the leaves, called stomata, absorb carbon dioxide. The guard cells control the opening and closing of stomata on the leaves.

All leaves contain chlorophyll. The chlorophyll is responsible for the green colour of the leaves. The chlorophyll traps sunlight and uses solar energy to produce food from carbon dioxide and water. Therefore, to produce food, plants require sunlight, water and carbon dioxide. The process by which plants produce their own food from sunlight, carbon dioxide and water is called photosynthesis. Photosynthesis is an exclusive process that takes place in plants and some algae. It uses solar energy.

Therefore, you can imagine the importance of photosynthesis for maintaining life on earth. Without photosynthesis, there will be no food, since all animals depend indirectly or directly on the plants for food. Without food for plants, life is impossible on earth.

At the time of photosynthesis, the chlorophyll present on the leaves uses sunlight, water and carbon dioxide to produce carbohydrates. Carbohydrate or starch is the food for the plant. The equation for photosynthesis is:

$\text{Carbon dioxide + water} \xrightarrow[Chlorophyll]{Sunlight} \text{Carbohydrate + oxygen}$

As you can see in the equation, oxygen is known to release during photosynthesis. The carbohydrate thus formed is converted to starch, which is another carbohydrate. Photosynthesis is indicated by the presence of starch in the leaves.

Green plants do not only conduct photosynthesis. Yellow, red or multicoloured leaves also perform photosynthesis. Chlorophyll is also present in the leaves that are of other colours.

If you look at the pond or any other stagnant water bodies, you will observe green slimy patches on the water surface. These slimy patches are algae and contain chlorophyll, which makes them green coloured. With the help of these chlorophylls, algae, too, can make their food by the process of photosynthesis.

Every living body is made up of numerous tiny building blocks called cells. Cells play numerous functions in the body. During photosynthesis, the stomata are responsible for gaseous exchange. The opening and closing of stomata are controlled by the guide cells.

### 1.3 Other Modes of Nutrition in Plants

Not all plants contain chlorophyll. For example, you will often find yellow tubular plants twining around the stem of other plants. It is called Cuscuta and they do not contain chlorophyll. Then how exactly do they get their food? Such plants that lack chlorophyll obtain food by heterotrophic nutrition mode. That means that the plants obtain food from other living organisms. The other living organism is called the host. If the plants deprive the valuable nutrients of the host, they are called parasites. You have often come across the word parasite in terms of insects and other animals. But can plants also be a parasite? Well, yes!

Do you know that plants can also eat animals? Yes, they do so. For example, a pitcher plant has a pitcher shaped structure which is a modification of a leaf. It has a lid at the top which closes when any insect (prey) falls into the pitcher. Some hairs directed downwards on the inside of the pitcher. These plants are insect-eating and known as insectivorous plants.

### 1.4 Saprotrophs

You must have seen mushrooms selling in the market. They are club-shaped structures mostly white or cream in colour. If they do not contain chlorophyll, then how do they prepare their food?

Mushrooms are fungi. They are not plants and they obtain food from other nutrition modes. They secrete digestive juices and chemicals on decaying or dead organic matters and extract nutrients from them. Such nutrition mode is called the saprophytic nutrition mode and the fungi are known as saprotrophs.

You will also find fungi growing on leather, pickle, bread and other surfaces, which are kept in hot and humid weather for a long time.

You will find most fungi in rainy seasons. These saprotrophs are the reasons why most food and clothes get spoiled in this season. The fungi propagate with the help of spores that can travel through the air. Once these spores come in contact with a wet surface, they can settle down, germinate and grow. So now you can understand why your food or wet clothes get spoiled in the rainy season.

There are other types of relationships between organisms. In one relationship, two organisms stay together since both of them are benefiting. For example, some fungi living in close association with the roots of some plants. They derive their nutrients from plants while providing nitrogen to the plants in return. Such a type of relationship where both the organisms are benefitted is called a symbiotic relationship.

In lichens, fungi and algae stay together. The alga delivers food it makes by photosynthesis. The fungus provides water, minerals, and shelter.

### 1.5 How Nutrients are Replenished in the Soil

If plants use all the minerals and nutrients from the soil, the levels of these nutrients in the soil are supposed to go down. To replenish the nutrient content of the soil, farmers often add manures and fertilizers to the soil. In this way, the nutrients are replenished, and it will support the continued growth of plants on this soil.

In general, soils require plenty of nitrogen for their growth. After each harvest, the soil gets devoid of nitrogen. To have further plantation on these soils, farmers often grow leguminous crops that can increase the nitrogen content of the soil. These leguminous crops like pulses, grams, dal, etc. are in a symbiotic relationship with a bacteria called rhizobium, which fixes atmospheric nitrogen into the soil. The bacteria obtain food and shelter in return from the plants. Growing leguminous crops in the field reduce the need to add nitrogen-containing artificial fertilizers in the soil.

In this CBSE Class 7 Science Chapter 1 nutrition in plants, you learned about plants that are autotrophs. You also learned about different nutrition modes amongst plants like heterotrophic, saprophytic, parasitic, insectivorous and symbiotic.

### Facts that Matter

• All organisms take food and utilize it to get energy for growth, maintenance and various life processes.

• Based on the mode of getting food, organisms are classified as autotrophs and heterotrophs.

• Autotrophs prepare their own food using simple inorganic materials like carbon dioxide and water.

• The essential requirements for photosynthesis are chlorophyll and sunlight.

• Heterotrophs are the organisms that cannot make food on its own and so they depend on autotrophs directly or indirectly for food.

• Parasitic, saprophytic, insectivorous and symbiotic are the different modes of heterotrophic nutrition in plants.

• Plants like Cuscuta are parasites as they take nutrition from the host plant.

• Saprotrophs like Fungi obtain nutrition from dead and decaying organic matter.

• Symbiotic relationship between Rhizobium and legumes helps in enriching the soil of the nitrogen that was lost.

• Leaves of the plants prepare the food so they are called the food factory of the plant.

• The important components of food are carbohydrates, fats, proteins, vitamins and minerals.

• Sun is the fundamental source of energy for all living organisms.

### Key Features of NCERT Solutions for Class 7 Science Chapter 1

Scoring good marks in the exam is essential for every student. To do so, students must have a clear idea about the subject. The next step would be to learn the solutions to important questions related to the subject. Experts at Vedantu have made Class 7th Science Chapter 1 solutions in a format that’s simple and easy to understand. Students can get benefits given below:

• Experts in the subject matter have designed the ch 1 Science Class 7 solutions. That is why the NCERT Class 7th Science Chapter 1 solutions can be considered as the most comprehensive, easy-to-understand, and to-the-point study materials for the students.

• Students have the unique facility of asking the experts whenever they face any problem.

• NCERT solution for Class 7 Science Chapter 1 has arranged all the concepts and equations in a proper sequence, thus saving the time for the students while they study.

• The students are encouraged to perform several Science experiments to understand the concepts.

• Since NCERT Class 7 Science Chapter 1 nutrition in plants can be downloaded, it allows the students to read and revise the concepts at their convenience.

• CBSE Class 7 Science Chapter 1 nutrition in plants PDF becomes more helpful when students plan for a quick revision before the examination.

• The NCERT solution for Class 7 Science Chapter 1 solutions promises a significant increase in marks for the students.

FAQs (Frequently Asked Questions)

1. How does the fungus get its nutrition?

Fungus is a saprotroph. Its mode of nutrition is called the saprotrophic mode of nutrition. It takes its food from dead and decaying organic matter. The digestive juices of fungus convert the dead materials into soluble form that get absorbed.

2. Explain the process, how nutrients are replenished in the soil.

The plants absorb mineral nutrients from the soil. The fertilizers and manures containing various nutrients like nitrogen, potassium and phosphorus need to be added from time to time to enrich the soil. The nitrogen gas is available in large amounts in the soil but cannot use it directly from the air. The bacterium Rhizobium lives in the roots of the leguminous plants. Rhizobium bacteria convert the non-usable form. In this way the nutrients are replenished in the soil by using fertilizers, manures and by sowing leguminous plants.

3. Explain the mechanism of eating insects by a pitcher plant?

The leaves of the pitcher plants are tailored into a pitcher like structure. The tip of the leaves form a lid that can open and close the mouth of the pitcher like structure of the leaves. There is hair inside the pitcher, which is directed downwards. When an insect lands in the pitcher gets entangled into the hair. The pitcher secretes some digestive juices that help the plant to digest the insect. Such insects eating plants are insectivorous plants. These plants do not get all the necessary nutrients from the soil. So, they are called partial heterotrophs.

4. How do I get marks in the exams with Vedantu’s study guide?

Vedantu has a team of very proficient and experienced teachers who understand the academic needs of every student. The subject matter experts have developed the study material in such a way that it is self-explanatory. The materials are also developed as per the latest guidelines from the CBSE board. You can not only download the pdf of the study guide but also reach out to the teachers if you have any doubts relating to the subject. This will definitely help you score more marks than before.

5. What do you mean by autotrophic nutrition according to Chapter 1 of Class 7th Science NCERT Textbook?

In the presence of sunshine, autotrophic nutrition is a process in which an organism creates its own sustenance from basic inorganic elements such as water, carbon dioxide, and mineral salts. The autotrophic mechanism of feeding is found in all green plants. This is a very interesting topic and the related processes are very necessary and hence the students must pay heed to each process involved. Visit the Vedantu site in case of any doubt or query regarding the same.

6. What do you mean by heterotrophic nutrition according to Chapter 1 of Class 7th Science NCERT Textbook?

Heterotrophic nutrition is defined as a method of nutrition in which certain species rely on other organisms for their survival. Heterotrophs are creatures that cannot manufacture their own food. Animals, fungi, and bacteria are all examples of heterotrophs. Because this is such an intriguing subject, students should pay close attention to the many procedures that go along with it. If you have any questions on the same, you can visit the Vedantu website.

7. What do you mean by chlorophyll according to Chapter 1 of Class 7th Science NCERT Textbook?

The chemical that gives plants their green hue is chlorophyll. During the biological process known as photosynthesis, it aids plants in absorbing energy and obtaining nutrients from sunlight. Many green foods contain chlorophyll, and some individuals take it as a supplement or apply it topically. In order for plants to begin photosynthesis, they would need this energy. Photosynthesis is the process through which water and carbon dioxide are converted into starches that plants may utilise as food.

8. What do you understand by photosynthesis according to Chapter 1 of Class 7th Science NCERT Textbook?

During photosynthesis, the light energy is converted into chemical energy by green plants and other organisms. Chloroplasts are tiny particles found inside plant cells that perform photosynthesis. Plants absorb carbon dioxide from the air and water from the earth via their roots. The Sun gives out light energy. The leaves release the oxygen that has been generated into the air. Since it is an important topic, do understand it properly along with all its components such as chloroplasts and so on.

9. How can I download the Solutions of Chapter 1 of Class 7th Science NCERT Textbook?

The solutions are easily available on the Vedantu site.

1. Click on this NCERT Solutions of Class 7 Science and choose Chapter 1.

2. The webpage with Vedantu’s solutions for Chapter 1 of Class 7th Science NCERT Textbook will open.

3. To download this, click on the Download PDF button and you can view the solutions offline.

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