Answer:
<em>Urine</em> is a liquid water material formed by kidneys
Answer:
Spider has a circulatory system
Answer:
yeah
Explanation:
there would be a shortage of oxygen. Unicellular organisms include bacteria.
The ultimate source of energy (for most ecosystems) is the sun<span>. The ultimate fate of energy in ecosystems is for it to be lost as heat. Energy and nutrients are passed from organism to organism through the food chain as one organism eats another.</span>