24. What is a possible evolutionary reason for the inverse relationship between the size of brains and testes in bats?

b. the carbon cycle ensures living things have a source of hydrogen

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.

the answer would be   10%

if you listed your answers right then i believe your answer is b.