The Open Door Web Site
How Plants Feed
 Reference chapter

Question 1
HTML version
PDF version

The following experiment was set up to investigate how a pondweed breathes in the light and in the dark.

Note: The carbon dioxide indicator is a coloured liquid which does not harm the plant. It can have three colours:

Purple or violet = No carbon dioxide
Red = A little carbon dioxide
Yellow = A lot of carbon dioxide

At the beginning of the experiment the carbon dioxide indicator was red. All three tubes were left in the light for a few hours. Then the colour of the indicator liquid was recorded.
 

1. Why was the aluminium foil wrapped around tube B?   
2. Why were the tubes filled to the top with liquid and stoppered with rubber bungs?   
3. Tube C had no plant in it, just indicator liquid. Why was it important to include this tube in the experiment?   
4. Colour the tubes in the diagram opposite in the colours you think they should have after a few hours.

 

5. What does this experiment tell you about the way green plants, such as the pondweed, exchange gases in the light and in the dark?  

 

 

 

 
Homepage

IB Biology Web

Biology Homepage

Biology Chapters Index

Topic Chapters

Facts and Figures

Laboratory Work

Questions and Quizzes Index

> Questions and Quizzes

Listings, Recognitions and Awards

EABJM Teachers' Resource Centre

EABJM Public Web Site

This Site was last
updated on 04/01/08
© The Open Door Team
Any questions or problems regarding this site should be addressed to the webmaster

© Paul Billiet, Shirley Burchill 2008