Like these, also, they respire oxygen, and are independent of light; and their various powers of growth, secretion, and general metabolism, irritability, and response to external factors show similar specific variations in both cases.
A few tissues (e.g. red blood cells, eye lens) have no mitochondria, and cannot respire aerobically.
This lacunar system not only enables the cells of the cortex itself to respire, but also forms channels through whicF air can pass to the deeper lying tissues.
Feeding relationships The main interactions in an ecosystem involve food, which all living organisms need as fuel to respire for energy.