Topic: Genetically modified organisms in the service of mankind

Target group

High school / technical school student

Core curriculum

General requirements

V. Reasoning and applying the acquired knowledge to solving biological problems. Student:

1. interprets information and explains causal relationships between processes and phenomena, formulates conclusions.

Specific requirements

XV. Biotechnology. Basics of genetic engineering. Student:

7. presents the potential benefits and threats resulting from the use of genetically modified organisms in agriculture, industry, medicine and scientific research; gives examples of products obtained using genetically modified organisms.

General aim of education

You will learn the methods used for the genetic modification of microorganisms

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• describe methods of genetic modification of microorganisms;

• determine the relevance of the genetically modified organisms;

• assess the suitability of genetically modified organisms for human needs.

Methods/techniques

• expository

  • talk.

• activating

  • discussion.

• exposing

  • exposition.

• programmed

  • with computer;

  • with e‑textbook.

• practical

  • exercices concerned.

Forms of work

• individual activity;

• activity in pairs;

• activity in groups;

• collective activity.

Teaching aids

• e‑textbook;

• notebook and crayons/felt‑tip pens;

• interactive whiteboard, tablets/computers.

Lesson plan overview

Before classes

• Students get acquainted with the content of the abstract. They prepare to work on the lesson in such a way to be able to summarize the material read in their own words and solve the tasks themselves.

Introduction

• The teacher gives the topic, the goals of the lesson in a language understandable for the student, and the criteria of success.

• The teacher asks one of the students to explain what is a vector in biological terms and to mention all associations with transformation. It directs the discussion towards DNA transformation..

Realization

• The lecturer designates people who will discuss the following topics in sequence: placing foreign DNA in the cell using genetic vectors; transformation with genetic vectors placing foreign DNA in the cell by electroporation; placing foreign DNA in the cell by means of micro‑shooting; genetically modified microorganisms and drug production.

• The pupils refer in turn to the assigned topics..

• Participants familiarize themselves with the content presented in the interactive illustration. Then the teacher discusses the issues with the students.

• The teacher explains that you can also modify the genome of multicellular organisms. The moderator cites an example of using genetically modified bacteria containing a gene responsible for producing a fluorescent protein as a display. Then it initiates a discussion on the potential benefits of using genetically modified microorganisms.

• He explains to pupils issues related to transformation. It informs that it is the introduction (transfer) of foreign DNA into a cell or the entire plant and animal organism to obtain transgenic organisms. It is carried out using vectors (bacterial‑plasmids, viruses) or non‑vector (micro‑shooting, microinfection). For the transformation of plants, bacterial vectors of the Agrobacterium genus are commonly used, which is often called agro‑infection and also occurs in the natural environment in the soil..

• Students carry out the interactive exercises checking the level of knowledge learned during the lesson. The teacher initiates a discussion during which the correct solutions for all the exercises performed by the students are discussed.

Summary

• The teacher asks a willing student to summarize the lesson from his point of view. He asks other students if they would like to add anything to their colleague's statements.

• At the end of the lesson the teacher asks: If there was going to be a test on the material we have covered today, what questions do you think would you have to answer? If the students do not manage to name all the most important questions, the teacher may complement their suggestions.

Homework

• Imagine that you have the opportunity to interview an academic - a specialist in the field of today's lesson. What questions would you like to ask him? Write them down.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Genetically modified organisms in the service of mankind

In order to genetically modify an organism (e.g. make bacteria produce insuline), first from the organism that produces this hormone, a fragment which codes the right protein needs to be cut out. The cut out DNA fragment is then placed in the genetic vector, which can be a virus or a plasmid. Plasmids are nucleic acid molecules that occur in a bacterial cell outside its „chromosome” and are capable of self‑replication. Such a vector is introduced into a recipient organism (e.g. bacterial cell) that synthesizes proteins encoded in the introduced DNA.

Another possibility of introducing foreign DNA into a cell is electroporation. This method uses a series of electrical impulses which create pores in the cell membrane through which the foreign DNA can penetrate the cell intended for the genetic modification. Electroporation is also used in cancer treatment, when the medicine cannot penetrate the tumor.

Biolistic transfromation is a method involving introduction of small balls (usually gold or tungsten) coated in DNA, which serve as bullets. These balls accelerated to high speeds (up to several m/s) by the so‑called gene gun penetrate the cell membrane and enter the cell, introducing the foreign DNA material. These bombed cells are being grown. After a certain period of time, it is checked if the DNA has been built into the genome. Unfortunately, the biolistic transfromation is a flawed method –gene guns are expensive and the method itself is not effective, as it causes mechanical damage to the cells.

Biotechnology uses microorganisms to produce proteins, hormones and vitamins. Currently, yeasts which have the gene responsible for the production of insulin (obtained by genetic engineering) are used to produce one of the human hormones – insulin, which regulates the blood sugar level.

The human growth hormone is another example of a substance produced using genetically modified microorganisms. This hormone is administered to children suffering from dwarfism, whose pituitary gland does not produce enough of the hormone. This prevents the development of the disease or reduces its effects.

Another substance which is produced thanks to the genetic modification is hirudin – a substance produced by leeches, which reduces blood clotting. It is used when patients suffer from thrombosis or vascular embolism. It prevents platelets from sticking together and eliminates clots that block the blood flow and cause oedema. The possibility of transferring the gene responsible for production of hirudin from leeches to microorganisms allowed the industrial production of this medicine.

The ability to create vaccines is one of the most important use of the genetically modified organisms. In 2013 first influenza vaccine was created which contains proteins derived from insect cells. The time needed to produce such a vaccine was much shorter than that needed for previous methods, which is immensly important when the influenza virus undergoes numerous mutations. Professor Andrzej Legocki bred in Poland lettuce, which contained the vaccine against Hepatitis B (HBV). In order to obtain it, he used the bacteria causing plant diseases, which enables the insertion of foreign DNA into a plant genome. Using this bacteria, he inserted the genes coding the proteins, which appear on the surface of the Hepatitis B virus, in the lettuce genome. The first phase of the research was carried out on mice, which ate the genetically modified lettuce. This way the mice received substance which helped them fight the infection caused by the HBV and avoid it.

• In order to insert foreign genes into cells, various cloning‑based and non‑cloning methods are used.

• by using microorganisms it is possible to produce useful substances (e.g. medicine)