Answer:
It is important because plants respond to light depend, logically enough, on the plant's ability to sense light. Phototropism is a directional response that allows plants to grow towards, or in some cases away from, a source of light. Photoperiodism is the regulation of physiology or development in response to day length.
The word isotonic is used to refer to the solutions (two solutions) which have the same osmotic pressure in both sides of the semipermiable membrane. The condition allows the free movement of water across the membrane. However, this does not change the concentration of the solution across the membrane.
Hence, osmosis may not occur in this condition.
The circulatory system helps the excretory and digestive system do their jobs because the waste from the blood in the circulatory system is eliminated from the body through the excretory system, and the nutrients absorbed by the digestive system are transported through the blood.
