Types of Quarks That Make Up Protons, Neutrons
This page is the CodyCross answer for the clue below from Past and Present Tech, Group 1445, Puzzle 2 (Typewriter).
Question is: Types of Quarks That Make Up Protons, Neutrons
and the answer is: UPANDDOWN
Word Meaning:
UP AND DOWN — Upward and downward, alternately.
Definitions from Wiktionary.