Final answer:
An organism with a growth temperature range of 45°C to 60°C is a thermophile, which is adapted to live in high-temperature environments through specific cellular adaptations. Mesophiles grow best in moderate temperatures and include many human pathogens, while psychrophiles are adapted to very cold environments.
Step-by-step explanation:
An organism with a temperature growth range of 45°C to 60°C would be categorized as a thermophile. Thermophiles are adapted to life at high temperatures, typically above 50°C. The adaptations necessary for such environments include changes in the composition of membrane lipids and proteins to maintain functionality at these elevated temperatures. Examples of such microorganisms include certain bacteria and archaea, and even some eukaryotic fungi that are important in commercial composting operations.
In contrast, mesophiles are organisms that grow best at moderate temperatures (20°C to about 45°C), including many human pathogens and organisms involved in food preparation like cheese and yogurt.