Think about what you need to stay alive. Consider how this might apply to yeast. Why do you think sugar was added to the yeast-and-water mixture?

In warm sugar water the yeast will grow and continue to feed on the sugar until it is all gone and as it does this it'll create waste products that are used both in beer and bread.

answer; ///i believe that the correct answer is (d); ///

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.