“…Accordingly, successful acquisition of theoretical genetics concepts requires students to reason hypothetico-deductively. Yet, research indicates that substantial percentages of college undergraduates have failed to acquire such reasoning skills (Cantu & Herron, 1978;Gipson, Abraham, & Renner, 1989;Killian, 1979;Lawson, 1982;Thorton & Fuller, 1981;Walker, Hendrix, & Mertens, 1980;Walker, Mertens, & Hendrix, 1979;Ward & Herron, 1980). Not surprisingly, genetics has been recognized as one of the most difficult topics for undergraduates (Lawson, 1992;Mitchell & Lawson, 1988).…”