1. This scenario is controlled due to the fact that they usually <span>test the effect of fertilizer, water and sunlight. Two last points pose as explanation for the second part of question.
2. It </span>can not be considered a theory because often it is supported by <span> hypothesis, so it's not direct thesis.
3. The way to know </span>that the y-axis is measuring the growth of the plant is to look at the graph and see that it <span>shows plant growing up.</span>
If you are asking a true/false question then the answer is true.
The Body Structures of some species support Darwin's Theories because of fossil records, similarities in DNA and protein sequences between organisms, homologous <span>and vestigial body structures, and similarities in early development. Also, they have similar limbs.
I hope this helps. C:</span>