Finnish upper secondary school biology textbooks

have outdated gene models

Tuomas Aivelo & Anna Uitto

University of Helsinki, Institute of Biotechnology / Department of Teacher Education

NFSUN - 6.6.2014

Method

Results D

iscussionIntroContents of genetics education

• International push to re-examine genetics education (Venville & Treagust, 1998; Shaw et al., 2008; Dougherty, 2010; Redfield, 2012)

Dramatic change in the nature of genetics and issues relating to it – but

not in teaching

Method

Results D

iscussionIntro”Canonical” approach

• Mendelian gene models• Monohybrid crosses,

dihybrid crosses,…• Is it outdated?

Method

Results D

iscussionIntroFinnish curriculum

• Mandatory course Cells and heredity has goals:– Be familiar with the structure of genetic

information and how it transfers from cell-to-cell and generation-to-generation

– Know how genes control the cell’s functions– Know the basic principles of the laws of

inheritance(Finnish National Board of Education, 2004)

Method

Results D

iscussionIntroResearch interest

• How does this curriculum convert to contents in the textbooks?

• How the textbooks represent genes?

THE QUESTION:What kind of gene models the upper secondary school biology textbooks

include?

Intro M

ethod Results

Discussion

Method

Historical models of genes

Based on the work by Gericke & Hagberg (2007):•Mendelian – “genotype is the phenotype”

•Classical – “a gene is situated in the chromosome and leads to a phenotype”

•Biochemical-classical – “gene produces an enzyme which creates a phenotype”•Neoclassical – “DNA makes RNA makes protein”•Modern – “complex interaction between genes, gene products and environment”

Intro M

ethod Results

Discussion

Method

Central features of gene models

4. The relationship between genotype and phenotype

GENE 3. The ‘‘real’’ approach to defining the function of the gene

2. The relationship between organizational level and definition of gene function

1. The structure and function relationship of the gene

5. The relationship between environmental and genetic factors.

Intro M

ethod Results

Discussion

Method

The materials and methods

• 4 upper secondary school textbooks – almost all Finnish students use one of these books (Aivelo & Uitto, 2014)

Intro M

ethod Results

Discussion

Method

Analysis• Used content analysis (Neuendorf, 2002)

• Collected mentions of genes and analyzed the gene model (Gericke & Hagberg, 2010)

An example from textbook Bios, pp. 72-73

Intro M

ethod Results

Discussion

Results

Results: Highly similar textbooks

• In all four textbooks, the contents were highly similar and they were presented in similar order

Intro M

ethod Results

Discussion

Results

No modern gene models present!

Mendelian

Classical

Biochemical-classical

Neoclassical

Modern

Intro M

ethod Results

Discussion

Results

Only a few modern feature-variantsFeature- variants

1. Structure

2. Organization

3.Function

4.Phenotype

5.Environment

Models

Mendelian 11 % 20 %

39 %

54 %69 %Classical

31 % 14 %19 %

Biochemical-classical 23 %

Neoclassical 58 %21 % 47 % 4 %

10 %Modern 0 % 4 %

Non-historic 45 % 14 % 17 %

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ethod Results

Discussion

Results

Not only similar to each other…Feature– variants

This study

Gericke &Hagberg

1a 11% 17%1b 31% 18%1c 58% 53%1d 0% 12%

2Ia 20% 22%

2Ib 14% 14%2Ibx 38% 34%2Ic 21% 10%2Icx 7% 20%

 2IIa 100% 79%2IIb 0% 22%

3a 39% 44%3b 47% 54%3c 14% 2%

4a 54% 11%4b 19% 32%4c 23% 28%4d 4% 29%

5a 69% 79%5ax 17% 11%5b 10% 5%5c 4% 9%

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ethod Results

Discussion

Results

Gene models This study Gericke &Hagberg

MendelianClassicalBiochemical-classicalNeoclassicalModern

34% 25%7% 19%

28% 31%31% 34%0% 8%

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ethod Results

Discussion

Results

The structure and function of genes were presented as simple facts,

not as scientific models.

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ethod Results

Discussion

Results

Hereditary phenomena were not connected to the molecular phenomena.

Genotype to phenotype link wasn’t explained.

Intro M

ethod Results

Discussion

Results

The environmental effects on gene expression were rarely mentioned and even when mentioned, subordinate to genes.

There was also explicit distinction between genes and environment:

e.g. “Phenotype = Genotype + Environmental effects”.

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ethod Results

DiscussionD

iscussion

Scientific determism

- Genes and environment have interactions.

Hard genetic determism- Genes determine the phenotype

Soft genetic determism- Genes and environment have distinct effects.

In a related study we found evidence for this soft determinism in students’ perceptions!

(Aivelo & Uitto, 2014)

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ethod Results

DiscussionD

iscussion

genotype environment

phenotype

development

Scientific genetic determinism

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ethod Results

DiscussionD

iscussion

Do students understand the concept of gene as model?

• At the moment, it’s not easy• Different fields of biology uses different

models (Flodin, 2009)

• How to reconcile these different models?

Intro M

ethod Results

DiscussionD

iscussion

Implications for textbooks and teaching

• More coherence needed in gene models (Gericke, 2008)

• Need to adress internally conflicting models (Justi & Gilbert, 2003)

• Need to bridge everyday language (gene for…) to the scientific language

• Explain different meaning of genes (Snyder & Gerstein, 2003)

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ethod Results

DiscussionD

iscussion

Implications for curriculum

• Need to link molecular aspects (cells, DNA and genes) to hereditary aspects (genotype, phenotype)

• The most obvious question:

How I became me?

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ethod Results

DiscussionD

iscussion• Aivelo & Uitto 2014: Geenimallit lukion oppikirjoissa ja lukiolaisten käsityksiä geenien

toiminnasta. Natura 2/2004: 31-35.• Dougherty, 2010: It’s time to overhaul our outdated genetics curriculum. The American

Biology Teacher 4:4-7. doi: 10.1525/abt.2010.72.4.2• Finnish National Board of Education, 2004: National Core Curriculum for General Upper

Secondary Education Intended for Young People• Flodin, 2009: The Necessity of making visible concepts with multiple meanings in science

education: the use of the gene concept in a biology textbook. Science & Education 18:773-94. doi:10.1007/s11191-007-9127-1

• Gericke & Hagberg, 2007: Definition of historical models of gene function and their relation to students’ understanding of genetics. Science Education 16:849-881. doi: 10.1007/s11191-006-9064-4

• Gericke 2008: Science versus school-science – multiple models in genetics: the depiction of gene function in upper secondary textbooks and its influence on students’ understanding. PhD Thesis, Karlstadt University. LINK

• Gericke & Hagberg, 2010: Conceptual incoherence as a result of the use of multiple historical models in school textbooks. Research in Science Education 4:605-623. doi:10.1007/s11165-009-9136-y

• Justi & Gilbert 2003: Teachers' views on the nature of models. International Journal of Science Education 25:1369-1386. doi: 10.1080/0950069032000070324

• Neuendorf 2002: The content analysis guidebook. Thousand Oaks: Sage.• Redfield, 2012: ”Why do we have to learn this stuff?” – a new genetics for 21st century

students. PLoS Biology 10:e1001356. doi:10.1371/journal.pbio.1001356• Shaw et al. 2008: Essay contest reveals misconceptions of high school students in genetics

content. Genetics 178:1157-1168. doi:10.1534/genetics.107.084194• Snyger & Gerstein 2003: Defining genes in the genomics era. Science 300:258-260.

doi:10.1126/science.1084354• Venville & Treagust 1998: Exploring conceptual change in genetics using a

multidimensional interpretive framework. Journal of Research in Science Teaching 35:1031-1055. doi: 10.1002/(SICI)1098-2736(199811)35:9<1031::AID-TEA5>3.0.CO;2-E