What is excretion?

Excretion is accurately defined as the elimination of metabolic wastes from the body. This process is crucial for maintaining homeostasis and involves the removal of substances that are no longer needed or could be harmful if they accumulate. Metabolic wastes include substances like carbon dioxide, urea, and various salts, which are produced during cellular processes.

The kidneys play a key role in filtering blood to remove these waste products, while other organs, such as the liver and lungs, also contribute to the excretion of wastes in different forms. Understanding excretion is essential in animal management, as it impacts an organism's health and overall well-being, ensuring that harmful substances do not build up in the body.

The other options provided do not encapsulate the concept of excretion. The intake of food and nutrients refers to ingestion and is the opposite of excretion, while gas exchange pertains specifically to respiration, not waste elimination. Growth and development of cells involve processes that increase the size or number of cells, which again is unrelated to the removal of waste. Hence, the chosen answer clearly encapsulates the process of excretion.