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प्रश्न
Paheli noticed water being pulled up by a motor pump to an overhead tank of a five-storeyed building. She wondered how water moves up to great heights in the tall trees standing next to the building. Can you tell me why?
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उत्तर
The root cells absorb water and mineral salts from the soil. A continuous upward flow of water from the roots to the top of the plant is maintained due to the suction pull (transpiration pull). This suction pull is created due to the continuous loss of water from the leaf surface by the process of transpiration.
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संबंधित प्रश्न
The liquid connective tissue A circulates in our body continuously without stopping. This tissue contains a pigment B which imparts it a colour C. The tissue A consists of four components D, E, F and G. The component D fights infection and protects us from diseases. The component E helps in the clotting of tissue A if a person gets a cut. The component F is a liquid which consists mainly of water with many substances dissolved in it and component G carries oxygen from the lungs to all the parts of the body.
(a) What is (i) tissue A (ii) pigment B, and (iii) colour C?
(b) Name (i) D (ii) E (iii) F, and (iv) G.
(c) Name one substance (other than oxygen) which is transported by tissue A in the human body.
(d) Which two components of tissue A are the cells without nucleus?
(e) Name any two organisms ( animals) which do not have liquid like A in their body.
What is the shape of RBC in human blood?
Direction: In each of the following questions a statement of assertion (A) is given and a corresponding statement of Reason (R) is given just below it. Mark the correct statement as.
Assertion: RBC plays an important role in the transport of respiratory gases.
Reason: RBC does not have cell organelles and a nucleus.
The volume of blood in human adults is ______.
Crab has blue blood.
Single circulation i.e. blood flows through the heart only once during one cycle of passage through the body, is exhibited by
Veins have valves that allow blood to flow only in one direction. Arteries do not have valves. Yet the blood flows in one direction only. Can you explain why?
What is the special feature present in a human heart which does not allow mixing of blood when oxygen-rich and carbon dioxide-rich blood reach the heart?
Why is it called an artery if it does not carry oxygen-rich blood?
While learning to ride a bicycle Boojho lost his balance and fell. He got bruises on his knees and it started bleeding. However, the bleeding stopped after some time.
- Why did the bleeding stop?
- What would be the colour of the wounded area and why?
- Which type of blood cells are responsible for clotting of blood?
