F.2 ~~I.S. Living things and air

[匿名]

2008-03-23 3:26 am

1 State two differences between the balloon-bell jar model and the human
breathing system.

2 On a suuny morning,Jack was walking by apond. He saw the some tiny gas
bubbles on the surface of the water plants.He wanted toinvestigate the gas
bubbles and so he took some water plants back to his underground
laboratory and cultivated them under wate. After a few days,the water
plants started to turn yellow and did not give out gas bubbles anymore.
(Hint: It is very dark in the underground laboratory.)

(a)Why were there some tiny gas bubbles on top of the water plants in the
pond?
(b)(i) Why didn't the water plants that Jack cultivated give out gas bubbles?
(b)(ii) How can you carry out an experiment to prove your answer in b(i)

回答 (1)

用戶7369

2008-03-23 3:38 am

✔ 最佳答案

1. human's lung consist of many tiny air sac but the bell jar model.
human's lung is protected by ribs which can move inwards and
outwards but the bell jar cannot.
2.a) the water plant undergoes photosynthesis. oxygen is then
produced.
b) there is no light in the underground laboratory.
so the plant cannot make photosynthesis.
so oxygen cannot be released.
c) we can put a light source , such as table lamp, near the plant.
if gas bubbles appear again, it proves that light is needed
in photosynthesis.

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