<span>The precision of scientific calculations is limited by the measurement that's the least precise out of all the measurements used in the calculation. When considering significant figures, the last answer should have the least significant figures out of all the measurements that entered into account and were able to be done with the most significant figures that could be directly measured. So, as more precise we are in measurements, more precise can be the final answer to a scientific calculation.</span>
Building models doesn't actually help scientists observe phenomena. Scientists build models to describe how nature and systems operate then make observations to see if their models match what they observe. Models which don't match what they observe are either alterated or scrapped. Good models are kept and used by the scientific community.
Plants do not breathe, they only respire. No such respiratory organ os present in plants. The carbon dioxide produced in animals during respiration is released to the atmosphere, whereas the carbondioxide produced during plant respiration may be used by the plant for carrying out photosynthesis.
The oceans cover 71 percent of the Earth's surface and contain 97 percent of the Earth's water. Less than 1 percent of the Earth's water is fresh water, and 2-3 percent is contained in glaciers and ice caps. The oceans contain 99 percent of the living space on the planet.