A: Sort of. Actually, a motion can be amended only by the assembly, not by an individual member. Any member may move to amend a motion before its adoption, but the amendment only happens if a majority of those voting are in favor of it.

Here's an example of how it goes:
SMITH: I move to paint the club house red.
WESSON: Second.
CHAIR: It is moved and seconded to paint the club house red. Is there discussion?
JONES (who hates red): I move to amend the motion by striking out "red" and inserting "green."
DOW: Second.
CHAIR: It is moved and seconded to amend the motion by striking out "red" and inserting "green." Is there discussion?
CHAIR: (after any debate): The question is whether to amend the motion by striking out "red" and inserting "green." All those in favor, say "aye." All those opposed, say "no." The "noes" have it and the amendment is lost.
CHAIR: (continuing): The question is whether to paint the club house red. Is there further discussion?
CHAIR (after any debate): The question is whether to paint the club house red. All those in favor, say "aye." All those opposed, say "no." The "ayes" have it; the motion is adopted; we will paint the club house red.