Apologetics is a separate discipline from catechesis, but in today's world the catechist, especially one dealing with older teens or adults, is likely to face the same questions as the apologist. Many teens come from a home where parents have not themselves been properly catechized, and so hold beliefs contrary to Church teachings. Or they come from a home of a mixed or no religious tradition. Then the catechist finds himself straying into the territory of the apologist. An exposure to apologetics is therefore useful.
Peter Kreeft writes at the Catholic Education Resource Center on A Philosophical Refutation of Reductionism.