NCERT Solutions for Class 7 Science Chapter 2 : Nutrition in Animals


What makes the blood look red?


Blood appears red because of the presence of a red-coloured pigment in red blood cells called haemoglobin. This pigment binds with oxygen and carries it to all parts of body.


Why is it necessary to excrete waste products?


Waste products need to be excreted because these are toxic in nature and their circulation or presence in body cause damage to various organs of the body.


Why is blood needed by all the parts of a body?


Blood is the only means of supplying oxygen and nutrients derived from digested food to all parts of the body and removing waste products from them. As blood is the sole means of transport of materials, it is needed by all parts of the body.


What are the components of blood?


There are four major components of blood:

  1. Plasma
  2. Red blood cells
  3. White blood cells
  4. Platelets


Does transpiration serve any useful function in the plants? Explain.


Transpiration is the loss of water molecules from stomata that causes a suction pull on the water column in xylem. Due to this suction pressure, water is transported to a great height in large trees through the xylem.


Choose the correct option:
(a) In plants, water is transported through
(i) xylem
(ii) phloem
(iii) stomata
(iv) root hair

(b) Water absorption through roots can be increased by keeping the plants
(i) in the shade
(ii) in dim light
(iii) under the fan
(iv) covered with a polythene bag


(a) In plants, water is transported through (i) xylem
(b) Water absorption through roots can be increased by keeping the plants (iii) under the fan


Match the structures given in Column I with functions given in Column II.
Column I Column II
(i) Stomata (a) Absorption of water
(ii) Xylem (b) Transpiration
(iii) Root hairs (c) Transport of food
(iv) Phloem (d) Transport of water
(e) Synthesis of carbohydrates


The correctly matched contents of Column I with Column II are as follows:

Column I

Column II

(i) Stomata

(b) Transpiration

(ii) Xylem

(d) Transport of water

(iii) Root hairs

(a) Absorption of water

(iv) Phloem

(c) Transport of food


Describe the function of the heart.


Heart is a muscular organ that pumps blood to each and every organ of the body. It helps in pumping the blood to lungs for oxygenation. Pumping action of heart keeps blood circulating in the vessels through which various important substances, like respiratory gases and nutrients, are transported. Heart consists of two atria and two ventricles, which contract and relax rhythmically to give rise to the pumping action.


What are stomata? Give two functions of stomata.


Stomata are small pores present on the surface of the leaves forming an opening for exchange of materials. Two important functions of stomata are as follows:

  1. Stomata allow exchange of gases, that is, intake of carbon dioxide and release of oxygen through it.
  2. Stomata regulate rate of evaporation of water from the leaf surface, which is called transpiration.


What will happen if there are no platelets in the blood?


In the absence of platelets, clot formation will not take place that will result in severe blood loss in case of injury. When a blood vessel is injured, platelets form blood clot that covers the wound protecting it from disease causing microorganisms and preventing blood loss.


Why is transport of materials necessary in a plant or in an animal? Explain.


The transport of materials is necessary in all organisms because it allows exchange of gases, supply of nutrients and removal of waste materials. All plants and animals have well developed transport systems to ensure continuous supply of oxygen, water and food to all parts of the body. Also, the toxic waste materials generated due to various activities is removed from the body by means of transport system only.


Draw a diagram of the human excretory system and label the various parts.


A well-labelled diagram of human excretory system is as follows:


Fill in the blanks.

(i) The blood from the heart is transported to all parts of the body by the ___________.
(ii) Haemoglobin is present in __________ cells.
(iii) Arteries and veins are joined by a network of ________.
(iv) The rhythmic expansion and contraction of the heart is called ___________.
(v) The main excretory product in human beings is _________.
(vi) Sweat contains water and _________.
(vii) Kidneys eliminate the waste materials in the liquid form called __________.
(viii) Water reaches great heights in the trees because of suction pull caused by ____________.


(i) arteries
(ii) red blood
(iii) capillaries
(iv) Heartbeat
(v) urea
(vi) salts
(vii) urine
(viii) transpiration

Benefits of NCERT Solutions

Following are some of the benefits of using NCERT Solutions by Extramarks.

1. The NCERT solutions for class 7 are prepared keeping in mind the necessary rules and format issued by the CBSE board thus providing students much-needed preview of the exam pattern of questions and preview of the exam that they are going to face during the final exams.

2. The students can be sure about the quality of the solutions as they are committed by highly experienced and expert teachers. These teachers have years of experience and they make sure that there is no mistake committed when preparing the solutions.

3. The NCERT 7 solutions are provided for the questions that are most likely to appear in the exam thus improving the efficiency of the students by helping them prepare for the important parts of the syllabus.

Tips & Strategies for Class 7 Exam Preparation

1. Start your revision early so you can revise well and grasp all the difficult concepts.

2. Organize your study time by making a timetable as it will help you manage your time accordingly.

3. Take mock tests and solve sample papers as they will help you learn time management during the exam and make you familiar with the exam pattern.

4. Take regular breaks, look after yourself by sleeping properly and eating well.

5. Know your exam well, explore the mock tests, and practice sample papers as much as you can.

Why Choose Extramarks CBSE Class 7 Study Materials?

1. The solutions have been compiled keeping in mind the purpose of scoring high marks in exams thus they have everything that the students need to prepare for exams.
2. The NCERT solutions for class 7 are designed in a clear and simple language complete with diagrams so that the students understand the subject well.
3. The NCERT 7 solutions are accurate thus improving their reliability.
4. The solutions are designed by expert and experienced teachers that help in removing all doubts out of the solutions and improving the credibility of the answers.

Frequently Asked Questions

Is class 7 Math NCERT book sufficient for prepare for the exams?

Yes, the NCERT book has been designed keeping in mind the pattern of paper that will be presented in the exam to students. The NCERT book is sufficient to study for the exam as it has everything related to the exam and contains all information out of which the questions will be asked in the exam. But if you want to prepare a little bit extra, we suggest that you go through the NCERT class 7 solutions.

When to refer to NCERT solutions for class 7th?

When you are studying the NCERT book for math and other subjects for your class 7 exams, refer to the NCERT class 7 solutions simultaneously so you can see where you are going wrong and what are you getting right in your exercises’ attempt.

Why are the NCERT solutions important for Class 7th?

The class 7th is very crucial as it is among the major middle school classes during which the child’s base is formed in math and science and even in other subjects like English. Thus, it is students must study smartly in this class and ace their exams while getting all the help they need from the NCERT 7 solutions given by Extramarks.

Can I rely on the NCERT solutions for class 7 Math at Extramarks to perform well in the annual exam?

Yes, absolutely. The NCERT solutions provided by Extramarks for class 7 are eloquent and elaborate at best and are thus useful for students studying for the final exams of class 7. The students will have many questions and doubts regarding the NCERT solutions for class 7 and this is why the solutions have been elaborated well to help students understand the answers to exercises.

Do you provide NCERT solutions for Class 7 Math for free?

Yes, the NCERT solutions for Math and other subjects for class 7 are available for free from Extramarks.

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