The term 'SUBJECT FOR GREGOR MENDEL' can be summarized by two crossword solutions: GENETICS (8 letters) and PEA (3 letters). Gregor Mendel was an Austrian monk and scientist who is known as the father of modern GENETICS. He conducted experiments on PEA plants in the mid-1800s, which led to his discovery of the laws of inheritance. His experiments focused on the genetic traits of PEA plants, such as flower color, seed shape, and pod color, and he used these results to develop his theories of GENETICS.