Final answer:
The largest living organism on Earth is a fungus, specifically a mycelium, located in an Oregon forest. This enormous organism covers 8.9 square kilometers and is still growing at around 2,400 years old.
Step-by-step explanation:
The largest living organism on Earth is not a plant or an animal, but it is actually a fungus, specifically a mycelium. This gigantic fungus, residing in an Oregon forest, is estimated to be 2,400 years old and spans an incredible 8.9 square kilometers (3.4 square miles), which is approximately the size of a small city. The extensive size of this living organism is due to its network of interconnected mycelia, which are the vegetative part of a fungus.
The concept of size in biological organisms varies dramatically among different life forms on our planet. From towering redwoods and extensive patches of kelp to massive fungal networks like this one in Oregon, the scale of living organisms can be astronomical. Cellular size, on the other hand, tends to remain microscopic, ensuring efficiency in nutrient absorption and waste elimination, which are vital for an organism's survival and growth.
In terms of individual plants receiving distinctive names, 'General Sherman' is often regarded as the largest living organism in terms of sheer volume, a giant tree in Sequoia National Park. However, when considering the total area covered and the mass, the Oregon fungus exceeds General Sherman, truly making it a monumental living organism.