A: Yes, by raising a Point of Order at a meeting at which a quorum is present. However, for the Point to be well-taken, you would need to present proof that a quorum had been absent, else a quorum is assumed to have been present. The presiding officer's ruling on the Point is subject to Appeal, in which case the assembly will - in effect - decide whether a quorum was present. See RONR pp. 343-44.