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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Biology => Topic started by: angelabean on July 13, 2022, 05:45:12 pm

Title: Photosynthesis question + experimental design
Post by: angelabean on July 13, 2022, 05:45:12 pm
How does the duration given for light exposure in Elodea affect the number of bubbles (oxygen) produced? What is the independent variable in this? I’m stuck on whether it’s the duration of time given for light exposure and/or whether the Elodea plant receives light exposure

As our control group is no light exposure for 15, 20, 25 minutes.
Title: Re: Photosynthesis question + experimental design
Post by: NN900 on July 15, 2022, 10:27:51 pm
How does the duration given for light exposure in Elodea affect the number of bubbles (oxygen) produced? What is the independent variable in this? I’m stuck on whether it’s the duration of time given for light exposure and/or whether the Elodea plant receives light exposure

As our control group is no light exposure for 15, 20, 25 minutes.

Hello angelabean,
For this, I would say it is more about how much light an Elodea is being exposed to. This is because as it absorbs more light (let's say it's light intensity), so if there's higher light intensity, it means that the rate of photosynthesis will increase. Thus, more oxygen bubbles will be produced. In saying this, the duration can also affect the number of bubbles being produced but it is not the main factor. (If it's possible, you can also check the changes in the pH level to see how light intensity can impact the amount of oxygen).
- For instance, if the plant is placed near the light source for 15 mins, it may produce more oxygen bubbles than the ones that are further away from the light source (even though, the duration it exposes to light is longer.)

Hope this helps.
Title: Re: Photosynthesis question + experimental design
Post by: angelabean on July 16, 2022, 12:50:38 pm
Thank you for your advice, I really appreciate it!