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.
A primary difference between plants and animals is the plantâs ability to manufacture its own food. In photosynthesis carbon dioxide from the air and water from the soil react with the sunâs energy to form carbohydrates (sugars and starches). Photosynthesis literally means to put together with light.