This case study was produced as an exercise in applying Vygotsky’s concepts of the MKO and the ZPD to a teaching situation.  Being a trained Molecular Biologist, I acted as the “More Knowledgeable Other” to provide the necessary information and to find a way to determine the Zone of Proximal Development in the student.

As such, I started with an overall goal – understanding of how the CRISPR/Cas9 system works and how it can be applied in a lab.  Based on this goal, I worked backwards to identify the concepts that would be necessary to allow a student with little biology knowledge to be able to reach the goal.

In order to help students understand the CRISPR/CAS9 system and its power, students first need to have a basic understanding of the Central Dogma of Molecular Biology; they also need an understanding of some basic Biochemistry as well as Genetics. Lastly, an understanding of the aims and basic challenges of Genetic Engineering will help them to have a better appreciation of the system.  The goal of the Molecular Biology Case Study was therefore to provide this scaffolding.

In an effort to avoid overwhelming the student and to keep the material accessible to a general audience, I decided to keep the background information relatively simple and avoided presenting details that were not necessary to the overall goal.

The content of the Case Study was structured to allow the participant to gradually learn the necessary concepts that would have to be used to understand the more complex/technical explanation of CRISPR.

In the process, multiple-choice questions are used to assess the learner’s level of understanding and ensure that the scaffold could be applied at an appropriate level.

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Here is a list of concepts that are introduced in the tutorial before the Biology behind the CRISPR/Cas9 System is explained:

1. Molecular Biology

• • Central Dogma of Molecular Biology
    • DNA is composed of two complementary strands which allow for easy DNA copying.
    • DNA is used as a template for the production of RNA molecules.
    • RNA in the form of mRNA is used as a set of instructions for the production of proteins.

2. Biochemistry

• • Proteins are the molecules that actually perform the functions of a cell.  DNA mutations can affect protein sequence, this could affect their 3D structure, and may impair their ability to function.

3. Genetics

• • Mutations that result in faulty proteins can be passed on to the next generation.

4. Genetic Engineering

• • This field aims to repair faulty genes or to introduce genes with desired function into an organism (ie. disease resistance in plants).