ζωογονήσει [1 verse] (noun sg fem dat) "Shall preserve" is  zōogoneō, which as a noun means "creation of life" and, as a verb ( verb 3rd sg fut ind act )  to "propagate or engender living creatures", of animals "breed", and "produce alive".  -- The word translated as "shall preserve" is by far the most interesting thing in this verse. Jesus only uses it here. It could be either the noun or the verb form of the same word. As a noun, it means "creation of life" As a verb, it means to "propagate" or, of animals "to breed". As a noun, it gives a reason for destroying, "he might, for a creation of life, destroy it." As a verb, it provides the result of destroying, "he might destroy, [then] he is going to propagate it".  The "then" is commonly assumed in these type of conditional statements.