Final answer:
The subject of this question is Biology, specifically the optimal growth temperature for certain organisms. Organisms such as bacteria, fungi, and microbes have preferred growth temperatures where their reproduction rate is highest. Some bacteria prefer body temperature (37°C).
Step-by-step explanation:
Based on the information provided, the subject of this question is Biology. Specifically, the concept being discussed is the optimal growth temperature for certain organisms.
Organisms such as bacteria, fungi, and microbes have preferred growth temperatures where their reproduction rate is highest. For example, mesophilic bacteria grow best at moderate temperatures in the range of 20°C to about 45°C. Some bacteria prefer body temperature, which is 37°C.
Therefore, the organisms that grow in dark reservoirs, require water, nourishment, and oxygen, and are destroyed by heat or light, are likely to be mesophilic bacteria, fungi, or microbes that have an optimal growth temperature around body temperature (37°C).