Q16 of 42 Page 192

Water is absorbed by roots and lost through leaves. How does this happen?

Water is absorbed by the root of the plant but has to be transported to different parts of the plant like leaves and stem. It is done through xylem tissues. The flow of water and minerals in xylem is unidirectional that is from roots to leaves. The process of movement of water in the plants through xylem and its evaporation through leaves or stem is known as transpiration. It is done through stomata during the daytime. It is important as it creates a pull which is known as transpirational pull because of which the water moves from the roots to the leaves.


More from this chapter

All 42 →
15

Plants absorb water from the soil. How does this water reach to the top of the tree? Explain in detail.

 16

How does food prepared by leaves is utilized by roots? Explain.

 17

Amit studied transportation in plants. He wanted to observe the process of transpiration and placed a plant in bright sunlight. He noted down his observations. Next day he asked his teacher few questions about his observations. Read the above passage and answer the following questions.

(i) What is the role of transpiration in plants?


(ii) Explain how the transpiration rate is affected by


(a) decreasing the humidity of the surrounding air.


(b) increasing the temperature of the surrounding


(iii) What values do you observe in Amit?

 18

Sumay studied about blood circulation in humans. He wanted to observe the flow of blood and was about to cut his finger a bit. He suddenly stopped realizing that this could be fatal. Read the above passage and answer the following questions.

(i) Why is the color of blood red?


(ii) Why does unclotted blood comes out from site of injury when platelets are present in the body?


(iii) Low count of which blood cells can make us vulnerable to infections?


(iv) What values do you think Sumay have?