Assertion [A]: Wine, bread and cakes are products of microbial activity.
Reason [R]: Yeast interacts or reacts with certain materials to make new substances.
Assertion [A] is True and Reason [R] is True and is a correct explanation for [A].
Yeast is a fungus used in the preparation of wine, bread and cake. It reacts with wheat dough for fermenting it. This fermented or changed product is bread.