In the latter case the resistance is caused by dissipation of mechanical energy when the configuration or the direction of flow is sharply changed, by the formation of vortices and secondary flows as a result of the flow breaking away, by the centrifugal forces, etc.
Animals depend on plants for food as plants produce food and energy which animals can't, so, herbivores eat plants to get energy, carnivores eat herbivores and other carnivores for energy and omnivores eat all four, plants, herbivores, carnivores and also other omnivores for energy.
Click Here to return to the search form. Plants do need oxygen to survive. They respire (take in oxygen, give off carbon dioxide) the same way that animals do. The difference is that during the day, plants also perform photosynthesis, in which they take in carbon dioxide and give off oxygen.