F2 1st Term IS WS 10 Answers

1st Term WS 10 Submission date：_____________ Name：______________________ Class & no.：2 _________(     )

7.5       Gaseous exchange between living

             things and the environment

i      Words to know:

	English term	Write the words again	Chinese term
1	Gaseous exchange	Gaseous exchange	氣體交換
2	Lungs	Lungs	肺
3	Respiration	Respiration	呼吸作用
4	Photosynthesis	Photosynthesis	光合作用
5	Greenhouse effect	Greenhouse effect	溫室效應
6	Global warming	Global warming	全球暖化

i      Matching:

Gaseous exchange	•	through which gases are taken in from and released to the environment.
Global warming	•	is caused by an excessive greenhouse effect.
Greenhouse effect	•	traps some of the heat from the sun to keeps the Earth warm.
Lungs	•	are parts of our breathing system for gaseous exchange.
Photosynthesis	•	is the process which produces food in green plants.
Respiration	•	is the process which releases energy in living cells.

i      Fill in the blanks:

1       Breathed air contains more carbon dioxide and less oxygen than unbreathed air.

2        Gaseous exchange occurs continuously between our body and the environment, through which animals (and plants) take in oxygen from air and release carbon dioxide to the environment.

3        In humans, gaseous exchange occurs inside the lungs.

4        During daytime, green plants consume carbon dioxide and produce oxygen in photosynthesis. In other words, green plants carry out photosynthesis at a faster rate than respiration.

                Amount of oxygen                                        Amount of oxygen
          produced in                         ­more / less      absorbed in
          photosynthesis                       than                respiration

           Therefore, it has a net uptake / release of oxygen.

                     Amount of carbon                                     Amount of carbon
           dioxide absorbed for           ­more              dioxide produced in
             photosynthesis                    than                  respiration

          Therefore, it has a net uptake of carbon dioxide.

5       At night, photosynthesis stops but respiration goes on in green plants. Therefore, they have net uptake of oxygen and net release of carbon dioxide.

6       The contents of oxygen and carbon dioxide in nature are kept more or less constant. This is known as the balance of oxygen and carbon dioxide in nature.

7       Greenhouse effect is the phenomenon that carbon dioxide (and some other gases) in the atmosphere traps some of the heat from the Sun and keeps the Earth warm.

8       The increasing amounts of carbon dioxide in the atmosphere lead to an excessive greenhouse     effect and hence global warming.