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.
Desert Conditions. The two main adaptations that desert animals must make are how to deal with lack of water and how to deal with extremes in temperature. Many desert animals avoid the heat of the desert by simply staying out of it as much as possible.esert Conditions. The two main adaptations that desert animals must make are how to deal with lack of water and how to deal with extremes in temperature. Many desert animals avoid the heat of the desert by simply staying out of it as much as possible.