Answer:
thermophile.
Explanation:
A thermophile is a kind of bacteria that belongs to the Archaea Domain and they are the kind of animals that can live in a region of high or extreme temperature. There has been a research on a kind of thermophile which is known as Methanopyrus kandleri which can exist in an extreme temperature of up to 500° C.
So, if we take a look at the question again we can see that after 48 hours and at 37°C 20,000 bacteria per milliliter are already in the tube and at more higher temperature of 55°C we have 1,568,000 bacteria per milliliter which means that at higher temperature more of the bacterial is produced.
Well there's Water, Earth, Fire, and Air. Not quite sure how this would be a school question. But here it is.
if a metal is an answer then that iis the answer.
Cells
Tissues
Organs
Organ system
Organism