Final answer:
The term used to describe the Roman teaching that the bread and wine in the Lord's Supper become the body and blood of Christ is called transubstantiation.
Step-by-step explanation:
The term that describes the Roman teaching that the bread and wine in the Lord's Supper become the body and blood of Christ is known as transubstantiation. This belief is central to Roman Catholic theology and is rooted in the words of Jesus during the Last Supper, as found in the Bible, where he established the sacrament of the Eucharist. According to Catholic doctrine, the substances of bread and wine are transformed into the actual body and blood of Christ, even though their appearances remain the same. This key difference distinguishes Roman Catholic and Eastern Orthodox beliefs from Protestant denominations, which often view the Eucharist as a symbolic remembrance rather than a literal transformation.