Is the Dhuhr prayer caught by catching the bowing of the second rak'ah before its time expires, or is it necessary to catch the entire first rak'ah with its two prostrations, unlike the Friday prayer for which it is sufficient to catch only the bowing to have caught it?

"Whoever catches the equivalent of one complete bowing (rak'ah) with its two prostrations (sajdatayn) before the time expires, has caught the prayer within its prescribed time (ada'an). As for whoever catches less than a complete bowing, the people of knowledge have differed: some are of the view that one does not catch the prayer with less than one complete bowing, while others are of the view that one catches it by catching a part of it, such as the opening takbeer or a prostration, adducing prophetic traditions as evidence."