Which of the following is not part of cell theory? А Cells are the basic unit of life in all organisms.

B All living things come from one or more cells.

C All cells must be able to make their own food.

D All cells come from existing cells.​

c. cells must be able to make their own food

C. All cells must be able to make their own food.

Explanation:

The other three are the cell theory. :)

But, C is NOT, so it's the answer. Most cells don't make their own food, so it isn't something that is considered part of the theory.

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.