Aim: To investigate whether living organisms by respiration convert oxygen into Co2.
The process by which organisms release energy from food is called respiration. There are two categories of respiration, depending on the amount of oxygen available. Aerobic respiration is the most common type of respiration. It requires oxygen- the reason why you are breathing right now. Anaerobic respiration requires no oxygen. The experiment which will take place is the aerobic respiration. Earthworms will be examined, to determine if oxygen is converted to carbon dioxide within the process.
Hypothesis: The earthworm will convert oxygen to carbon dioxide. Materials: filter pump, sodium hydroxide solution, limewater, several insects or worms.
1. Set up all the flasks in position, in the order of
sodium hydroxide solution, limewater, earth worms, limewater.
2. Slowly draw air through the apparatus by means of the filter pump. 3. Record any changes in the colour of the limewater in flasks B and D.
When air is drawn through the apparatus and flask A contains a chemical to remove all CO2 (sodium hydroxide), the limewater in flask D turns cloudy after a minute or two. This shows the presence of carbon dioxide. The limewater in flask B stays clear. This shows that the worms must be producing the carbon dioxide. Flask#
Oxygen has passed through
Presence of carbon dioxide
My hypothesis was true, the worms did convert the oxygen into carbon dioxide. There were plenty of reasons that could have affected the experiment such as, if the worms were dead, if the test was not fair, if the metabolic rate was low for the organisms or even if the lime water took time to process. However, the experiment went well and the results were clear.
In conclusion, we were able to see that organisms such as worms or insects produce carbon dioxide just like...
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