Discusses the frequent misconception displayed by students that chromosome structure is a function of chromosome number or ploidy. Provides detailed analyses of the evidence concerning the prevalence of this ploidy/structure misconception among students of introductory genetics and the potential sources for inaccurate communication that it can…

Student knowledge in a subject area prior to and after instruction has traditionally been assessed by administering a pre- and post-test, usually multiple choice, though recent studies criticize the use of even the best-constructed multiple choice tests. This study assessed college freshmen's knowledge before and after a laboratory experience in…

Investigates high school students' understanding of the physical relationship of chromosomes and genes as expressed in their conceptual models and in their ability to manipulate the models to explain solutions to dihybrid cross problems. Describes three typical models and three students' reasoning processes. Discusses four implications. (YP)