Assuming the graph that shows plant groups B and C have a lower growth rate than group A, this shows that every plants needs a certian amount of sunlight to grow. Since they get their energy from the sun, it is the most crucial to a plants survival. If plants dont get the energy they need to live, as producers, primary consumers dont get get energy from producers. If primary consumer cant get energy, neither can secondary consumer and so forth.
Answer:
The main function of the circulatory (or cardiovascular) system is to deliver oxygen to the body tissues, whilst simultaneously removing carbon dioxide produced by metabolism.
The correct answer would be:
<em>Cycles.</em>
