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.
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.
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.
There are four major components of blood:
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.
(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
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 |
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.
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:
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.
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.
A well-labelled diagram of human excretory system is as follows:
(i) arteries
(ii) red blood
(iii) capillaries
(iv) Heartbeat
(v) urea
(vi) salts
(vii) urine
(viii) transpiration
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 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.
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.
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.
Yes, the NCERT solutions for Math and other subjects for class 7 are available for free from Extramarks.
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