Final answer:
Leaf-cutter ants utilize antibiotic-producing bacteria in a mutualistic relationship to protect their fungi gardens from parasitic fungi, whereas humans use antibiotics to combat bacterial infections, often leading to environmental concerns of antibiotic resistance.
Step-by-step explanation:
The relationship between leaf-cutter ants and their antibiotic-producing bacteria differs from the use of antibiotics in medicine by humans in several ways. In the natural mutualistic relationship, leaf-cutter ants cultivate fungi as a food source. These gardens are threatened by parasitic fungi, which could destroy the ants' food source. To combat this, the ants house antibiotic-producing bacteria on their bodies that help to control the growth of parasitic fungi, ensuring the health of their cultivated fungi.
In contrast, humans use industrially produced antibiotics in medicine, primarily to combat bacterial infections. The antibiotics humans use are typically isolated and produced in large amounts, which can lead to concerns about the development of antibiotic resistance when these antibiotics are found at subinhibitory concentrations in the environment. This is a significant difference from the targeted, localized use of antibiotics by leaf-cutter ants, which is a result of coevolution and benefits both the ants and the fungi without leading to widespread resistance issues.