The Access Excellence Periodic Tableau

A Model of a Bacterial Plasmid

Therese Clark
Monsignor Kelly High School
Beaumont, TX

Type of entry:

Lesson/class activity

Type of activity:

Target audience:

Background information:

What question does this activity help students to answer?

This activity helps the student understand the mechanics involved with using a bacterial plasmid. The model allows the student to splice a gene into a plasmid.

Notes for the teacher:

This is an excellent model to use when covering the topic of manufacturing proteins by genetic engineering. It helps the student understand how the genetic instructions from one type of organism can be interpreted by another organism.

Required of students:

Students should read about the manufacturing of protein by genetic engineering. If a diagram is available in their textbook, this simulation allows the student to work through the diagram. Groups of students can manufacture their own "protein" by exchanging segments.

Preparation time:

If all of the materials are available, the model only takes about 30 minutes to make.

Class time needed:

If the teacher wants a class supply, then one class time will be necessary to make the model. Another class time should be used to discuss the role of plasmids in genetic engineering.

Abstract of Activity:

This model provides a manipulation for students to use in order to understand some of the techniques of recombinant DNA. Since bacterial plasmids are a vital part of the process of producing proteins by genetic engineering, this model begins by helping the student understand the definition of recombinant DNA (that is, the DNA from different organisms has be recombined). It also helps the student understand the use of special types of enzymes to cut the DNA from one organism and to be spliced into the DNA of another organism. A good example to use with this model is the manufacturing of human insulin by using recombinant DNA. A fragment of DNA which codes for human insulin is inserted into a bacterial plasmid. The bacterial cell takes the plasmid in and recombinant DNA replicates along with the DNA belonging to the bacterial cell. The bacteria with the plasmid containing the insulin gene replicates and the new cells can produce the insulin coded by the recombinant DNA.


Materials needed:

These materials will make two (2) plasmid models.


  1. Cut the handles off of the jump ropes. This can be done by cutting the blocking mechanisms on the plastic jump rope within the handle.

  2. Each jump rope should be cut into three unequal pieces. This helps illustrate the length of base pairs. This model has three segments with the following measurements: one segment - 1.3m, 2nd segment - .13m, and a third segment - .90m.

  3. Use a glue gun to attach each end of the plastic jump rope with one part of a connector set. Be sure all the segments attach to make a circular model.

Method of Evaluation/Assessment:

The following skills and activity should be assessed during the activity:

  1. The student should be able to construct a bacterial plasmid with the materials provided.

  2. The student should be able to use the model to define the following terms: recombinant DNA, gene cloning, genetic engineering, DNA sequencing.

  3. The student should be able to use the model to help explain other practical applications of genetic engineering.

  4. This model should help students the relationship between science and technology.

  5. The model should help the student understand how genetic engineering is used in research to demonstrate the order and function of genetic material.

Extension/Reinforcement/Additional Ideas:

  1. Have the students use their model to diagram the process used to form recombinant DNA.

  2. Have the students simulate the genetic engineering and manufacturing of proteins by exchanging fragments and explaining the use for the protein their new cell produces.

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