The term 'prefix with plasm' refers to a group of words that all begin with the prefix 'plasm-'. The six words in this group are ENDO (4 letters), NEO (3 letters), ECTO (4 letters), PROTO (5 letters), CYTO (4 letters), and ENTO (4 letters). ENDO means 'WITHIN', NEO means 'NEW', ECTO means 'OUTSIDE', PROTO means 'FIRST', CYTO means 'CELL', and ENTO means 'INSECT'. Together, these words describe different aspects of the same concept: the relationship between the inside and OUTSIDE of a CELL.