Photosynthesis questions

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Photosynthesis questions

Post by fifa » Mon Sep 28, 2009 8:10 pm

Heterotrophs are dependent on autotrophs for their food supply. Autotrophs can make their own food by __________________________.

All of these
feeding on bacteria and converting the nutrients into usable energy
None of these
synthesizing it from water and CO2
using light and simple chemicals to make reduced carbon compounds

I am not sure if heterotrophs feed on bacteria by converting their nutrients? So I think that eliminates all and feeding. Would the answer be just using light and simple chemicals to make reduced carbon compounds? If so, what are reduced carbon compounds?
Note: I put down synthesizing it from water and CO2 and that wasn't right.

Which of the following statements about photosynthesis is false?
The reactions of photosynthesis are simply the reverse of those found in cellular respiration.
All the O2 gas produced during photosynthesis comes from water.
CO2 is taken in, and water and O2 are released through stomata.
The water for photosynthesis in land plants comes primarily from the soil.
Light is absolutely necessary for the production of O2 and carbohydrates.

I know that carbon dixoide is taken in and water and oxygen are released. However, all four of the others seem true to me? Could it be that some oxygen gas actually comes from carbon dioxide? Or is it the last choice since there are dark reactions in photosynthesis aka calvin cycle? Please help!

Chlorophyll is suited for the capture of light energy because _________________.
certain wavelengths of light raise it to an excited state
chlorophyll's structure allows it to attach to thylakoid membranes
in its excited state chlorophyll gives off electrons
All of these.

Would it be all of these? I either think it is all or that the chlorophyll's structure allows it to attach to thykaloid membranes.

Thank you for your help!
Last edited by fifa on Tue Sep 29, 2009 3:36 am, edited 1 time in total.

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Post by canalon » Tue Sep 29, 2009 2:01 am


Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)

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