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.
Why do animals depend on plants. Plants give animals the food and shelter they need. Herbivores, which are plant eating animals, rely on plants to provide them with a regular source of food. They also provide shelter to may animals, both large and small.
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.