It helps break down waste and consume it as well as by eating dead organisms
Hope this helps :))
Answer:
Number of bacteria required 
Explanation:
Given -
Size of each bacterium
micrometers long
These bacteria are arranged end to end.
The size of chain to be formed is equal to
centimetres
Let us say that in forming a chain of
centimetres nearly X number of individual bacterium are required.
hence, number of bacterium required to form
centimetres chain can be represented as

Number of bacteria required 
I believe it is B but I’m not 100% sure
Answer:
A conversion factor is a numeric expression that enables feet to be changed to chains as an equal exchange. A conversion factor is a number used to change one set of units to another, by multiplying or dividing. When a conversion is necessary, the appropriate conversion factor to an equal value must be used.
— https://www.nwcg.gov/course/ffm/conversions/21-unit-conversion-and-conversion-factors#:~:text=A%20conversion%20factor%20is%20a,equal%20value%20must%20be%20used.