Essay contest reveals misconceptions of high school ... - Genetics

Genetics Education 1165mal recessive, or X-linked inheritance. Students wereoften unable to adequately describe sources of abnormalchromosome numbers. Essays did not mentionerrors during meiotic cell division and generation ofgametes as the source of monosomies or trisomies. Ourreview of state science standards for high school studentsin biology suggests, not surprisingly, that the majority ofstates provide specific, detailed standards that mandateteaching students, even at the earliest levels of their lifescience education in high school, the basic biology ofinheritance patterns. Although 15 of the 20 biologystandards included basic patterns of inheritance knowledge,when we reviewed the essays that were catalogedas having an error or a misconception falling under‘‘patterns of inheritance,’’ 80% of those essays inaccuratelydescribed a basic tenet of Mendelian inheritance,despite their expected coverage of this material at theircurrent grade level or in previous biology courses.Nature of genes and genetic material: All 20 statestandards examined require coverage of the nature ofDNA as the hereditary material in living things. Nevertheless,students suggested that lower organisms, includingbacteria and fungi, often do not carry DNA. Wealso noted student confusion regarding the hierarchalorganization of genetic material. Notably, students werefrequently unable to accurately define DNA, genes, andchromosomes. Often, these terms were instead usedinterchangeably. In 2007, ,1% of essays included anyinformation on additional genetic material in thegenome. Students did not mention gene expressioncontrol elements, repetitive sequences (unless discussingHuntington’s disease), or other nongene elementsin the genome. Finally, students often described specificprotein-encoding segments, or genes, as discrete elementsthat could easily be removed from one contextand added in a separate context. While this view likelyextends from students learning basic biotechnology andbacterial transformation techniques (for example, addingthe green fluorescent protein from jellyfish tobacterial strains), likening this process to the adding ofa chemical to a solution is an oversimplification, at best.Genetic basis of disease: One of the principle errorsobserved in this category was the confusion of ‘‘hereditary’’and ‘‘genetic’’ when describing diseases. In a smallsubset of cases, 10% of the total essays categorized ashaving a misconception in this topic, students completelymisrepresented the genetic nature of a specificillness (e.g., calling HIV-1 an inherited disorder). Whilemost illnesses have a genetic component, this does notmake them hereditary. Moreover, while even infectiousdiseases can be considered to have a genetic componentwhether it be of the genetics of the virus itself or howindividual genetics could result in different manifestationsof the same illness, students must learn to clarifythese differences. Cancer is a genetic disease. Only rarecancers, however, are hereditary. However, studentsoften described breast and ovarian cancer as hereditarydue to the mutations in BRCA1 or BRCA2. Whilemutations in these genes often do result in a cancerpredisposition that appears to be inherited in a dominant-likefashion, the majority of breast cancer cases arenot due to mutations in these genes.Genetics research: A large number of student essaysfocused on the promise of genetic engineering inhuman health and reproduction (see also the Reproductivetechnologies section). While superficially this reflectsthat students recognize the positive influence that thestudy of genetics can have in their lives, numerous misconceptionssuggest that students still fail to truly understandthe nature and limitations of genetic research.An examination of state science standards, briefly describedabove, reveals that while state and national process(not necessarily content) standards require coverageof the nature of scientific research, inquiry, and discovery,this does not necessarily equate to students learningabout how scientists actively perform research. Instead,these process standards reflect the fact that teachers areexpected to provide students with opportunities forinquiry and investigation in the context of their ownclassroom laboratory experiments and activities. Inshort, state science standards do not require studentsto learn about the nature of scientific research.Reproductive technologies: Misconceptions fallingunder the category of ‘‘reproductive technologies’’could have been accurately cataloged under genetictechnologies. However, this class of misconceptions wasfrequent enough to require special treatment. In thesecases students continued to explore their ideas ofgenetic engineering and cloning to describe the futureof reproductive control where prospective parents would‘‘improve’’ and ‘‘design’’ their offspring, with the ultimategoal of having the ‘‘perfect’’ child. Eugenics, eitherin specific use of terminology or in concept, appeared in15% of essays collected in 2007. This percentage is notreflective of the goals or ongoing work of genetics research.Unfortunately, its prevalence in student essays islikely due to both its historical role in research as well asthe ‘‘genohype.’’ Interestingly, the idea behind eugenicsis not overtly described in the standards of any statescience standards that we explored. The frequency of studentsdescribing using genetics to improve genotypesand design human beings, however, suggests that this iseither the hook that teachers are using or the messagethat students are hearing from the media. More researchwould be required to determine which of these optionsis most prevalent.DISCUSSIONRole of standards: State science standards are not theonly source of direction for what is taught in publicschools; textbooks, laboratories, statewide assessments,and teacher quality also play significant roles. These