biology bioleg
chemistry cemeg
consequence canlyniad
control rheolaeth
discipline disgyblaeth
discovery darganfyddiad
evidence tystiolaeth
fact ffaith
kernel hanfod
method dull
model patrwm
procedure dull
production cynnyrch
research ymchwil
science gwyddoniaeth
society cymdeithas
| | system system
technology technoleg
trouble trafferth
|