Final answer:
The statement in question is false; saprobes, including fungi and some protists, require organic matter as a carbon source for their growth and metabolism, playing a key role in the decomposition and nutrient recycling within ecosystems.
Step-by-step explanation:
The statement that saprobes do not need a carbon source for growth and metabolism is False. Saprobes, which include organisms such as fungi and certain protists, obtain their nutrients from dead or decomposing organic matter. They release enzymes to break down complex organic substances into simpler compounds that can be absorbed, such as glucose, which is used as an energy and carbon source for their growth and metabolism.
Fungi are predominantly saprobes and play a crucial ecological role in recycling nutrients. For instance, fungal exoenzymes can degrade cellulose and lignin of dead wood into glucose, providing carbon, nitrogen, and other elements back to the environment. This process is vital for maintaining ecosystem balance and allowing for new plant growth, which supports diverse food chains.
Similarly, saprobic protists, which are also saprobes, have an important function in returning inorganic nutrients to the soil and water, promoting the cycle of life. Therefore, saprobes depend on organic matter for their energy, growth, and reproduction, and their metabolism is integral to the health and sustainability of ecosystems.