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.
1 Plants, like animals, must have food in order to survive. 2  But, unlike most animals, plants make their own food or energy source through the process of photosynthesis. 3  Plants use this food, in the form of glucose, in the same way that animals use the glucose they eat: it is converted into ATP by the mitochondria.