132-133 — SCIENCE CURRICULUM TOPIC STUDY (CTS)

Difficulty with Concepts and Terminology

Students often mix up the terms ‘gene’, ‘chromosome’ and ‘DNA’ and have difficulty in understanding the relationship between them. Some students may think the words are synonyms for each other and mean the same thing (Lewis and Kattmann 2004).
A study of 16-year-old students in England and Wales showed a poor understanding of the processes by which genetic information is transferred and a lack of basic knowledge about the structures involved. There appeared to be widespread uncertainty and confusion over the use of genetics concepts such as genes and chromosomes (Lewis and Wood-Robinson 2000).

DNA

Several researchers (e.g. Lewis, Leach and Wood-Robinson, 2000; Wood-Robinson, Lewis and Leach, 2000; Witzig et al., 2013) have reported commonly held ideas about DNA, including that: a) DNA is alive; b) DNA is made of cells; c) DNA is only found in blood, or only in specific cell types; and d) some living organisms (e.g. plants and bacteria) do not have DNA.

Genes

Some students do not understand that genes are physically passed down from parents to offspring through DNA. Some think genes skip generations or that they get their genes from non-parental relatives such as aunts or uncles, not realizing that genes come directly from the individual’s parents (Freidenreich, Duncan, and Shea 2011).
A study conducted by the National Institutes of Health on high school students’ essays from a genetics essay contest revealed several genetics misconceptions. One of these is that students believe one gene is always responsible for one trait. This study also examined state standards and they found that only 3 of 20 state standards specifically mentioned that students should learn about polygenic inheritance. Thus, the researchers concluded that it is not surprising that we would see a common misconception that single genes are the cause of most traits and inherited diseases. (Shaw et al. 2008).
Researchers have shown that students have difficulty reasoning across different organization levels in genetics such as genes, proteins, cells, tissues, organs (Duncan and Reiser 2007).
In a study of a general population of adults, participants were asked an open-ended question of where genes were found. The brain and blood were common answers. 34% mentioned that all cells in the body contained genes. Only 14% mentioned DNA or chromosomes (Lanie et al. 2004).

Relationship between DNA, Genes, and Chromosomes

Many students not only struggle to define terms such as gene, DNA, and chromosome, they also have difficulty describing relationships between these terms and how they contribute to inheritance (Cisterna, Williams, and Merritt 2013).
In his research on common misconceptions related to heredity, Berthelsen (1999) found that many students do not understand the relationship among DNA, genes, and chromosomes.

Genetic Engineering

·An analysis of research carried out across many countries showed that most secondary students lack knowledge about genetic engineering, even in countries that produce genetically modified organisms nationally. They also found students’ attitudes toward genetic engineering were mostly negative (Purbosari and Astuti 2023).
A study by Fernbach (2019) showed that the less objective knowledge people had about science and genetics the more negative their attitude toward genetic engineering and products like genetically engineered foods.
A study by Vera and Vera (2014) found tha Czech female students had less knowledge of genetic engineering than males. Overall, both male and female students tend to have a negative attitude toward genetic engineering.