<u><em>1. The proper answer to this question is "the Sun".</em></u>
Reason:
<u><em>The Sun is the ultimate source of energy for organisms it allows plants to use photosynthesis </em></u><span><u><em>to convert light energy into energy for that organisms and other organisms.</em></u>
<em>Therefore the answer is the Sun.</em>
Here is your second answer:
<u><em>2. The proper answer to this question is "</em></u></span><u><em>photosynthesis".</em></u>
Reason:
<u><em>Photosynthesis is the process that plants use to change (convert) light energy into energy (that other organisms can use). For example a apple tree uses </em></u><span><u><em>photosynthesis to make apples for humans, and other organisms to consume for energy.</em></u>
<em>Therefore the answer is </em></span><span><em>photosynthesis!</em>
<em>To sum up the answers are:</em> <em>1.Sun</em> <em>2.P</em></span><span><em>hotosynthesis</em>