The answer is A) they provide a source of energy.
Answer: <u><em>D. An observation that has a number associated with it</em></u>
Explanation: The answer is D. An observation that has a number associated with it. I would explain further, but it is pretty self explanatory.
<em>Good luck!</em>
<span>Unicellular organisms would most likely have isogametes.
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The root would be the appropriate answer
Lysosomes, dead organelles, waste products and other unwanted substances are removed through lysosomes