Explanation:
To swim, they move their tails up and down, rather than back and forth as fishes do. This is because whales evolved from walking land mammals whose backbones did not naturally bend side to side, but up and down. ... Whales do the same thing as they swim, showing their ancient terrestrial heritage.
Cetaceans are fully aquatic marine mammals belonging to the order Artiodactyla, and branched off from other artiodactyls around 50 mya (million years ago). Cetaceans are thought to have evolved during the Eocene or earlier, sharing a closest common ancestor with hippopotamuses.
Is is plants that provide food, provide shelter, and prevent erosion, since plants are a major food source for many animals, as well as cover from rain and weather.
There's so much confusion going on between<span> the acronyms </span>RER<span> and RQ. At the state of rest the </span>RER<span>, completely known as the </span>respiratory exchange ratio<span>, is actually the same as RQ or </span>respiratory quotient<span>. ... The RQ is a metabolic </span>exchange<span> of gas </span>ratio<span> that is equal to CO2 production over oxygen uptake </span>
