how do we show the presence of respiration in living things?

Plz answer me in English

1 個解答

  • ?
    Lv 5
    1 十年前

    Firstly, set a open system, which is consisted of three bell jar. the first one contained lime water to absord Carbon dioxide, and connected to the second bell jar with a glass tube. The second bell jar contain the living thing (mouse as an example). And the second jar connect a U-shaped glass tube which contained coloured liquid and connect to third bell jar (nothing inside).

    if respiration occured, the side of liquid level near the second jar would be pushed down, and the other side rises.

    Because when the air come into the first jar, all carbon dioxide would be absorbed by lime water, so the air come into second jar would not contain any carbon dioxide.

    If the living thing respirated, it would expire carbon dioxide and the air pressure in second jar increased. So the air would go into the U-shaped tube and press down the liquod level.