If there is no oxygen , the cells go through anaerobic respiration which leads tot he build of lactic acid in the muscles. This is why we get sore and feel the burn during a workout.
Each cell is alive even if it is part of a multi celled body, and all living organisms consist of one or more cells. Also, cells reproduce by dividing so it follows that all existing cells must have arisen by division of other cells. As a cell divides it passes it hereditary material- its DNA- to offspring.
<span>"D.how living things are interconnected with their environment</span>" is the correct answer. Ecology has to do with systems of environments as a whole, and the organisms that live there.