If all of the characteristics of life are required to classify something as “alive”, how can we account for those individuals who are definitely alive, but that do not reproduce (for example, people without children or a sterile mule)?

Here is the answer key. Just scroll down to the question and the answer is there.

Explanation:

“People without children” then that is caused by external factors that causes mutation in genes or diseases, so you can not classify them as not alive sincetheir species (Parents) are able to reproduce. When it comes to mules, their sterility is caused by being a hybrid of donkey and horse (not the same specie). Example, the cells in the human or mule body reproducing constantly.

i would paraphrase! <3

b.have there own function.