Topic: The use of DNA research in science

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

VIII. Biotechnology. Basics of genetic engineering. Student:

3. presents the essence of techniques used in genetic engineering (DNA electrophoresis, PCR method, DNA sequencing).

General aim of education

The student acquires knowledge on the fields of science in which DNA research is used.

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• exchange and describe examples of the use of DNA research in science;

• assess the usefulness of knowledge acquired during the project of understanding the human HGP genome;

• explain the relationship between phylogenetics and molecular biology.

Methods/techniques

• expository

  • talk.

• activating

  • discussion.

• 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.

Realization

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

• The teacher appoints people who will discuss the following topics in turn:

  • genomic testing;

  • project of understanding the human genome;

  • use of bioinformatics in phylogenetics;

  • barkoding DNA

• Students refer to assigned issues. The teacher along with the class complements, if necessary, non‑exhaustive statements.

• On the basis of resources from the lessons in the e‑textbook, the lecturer demonstrates to the students instructions on using the NCBI server. Then, students working in groups compare the nucleotide sequence of mouse and rat albumin.

• Students perform exercises and commands. The teacher checks and supplements the answers, providing students with the necessary information. Provides feedback..

Summary

• The teacher briefly presents the most important issues discussed in class. He answers the additional questions of the proteges and explains all their doubts. Students complete notes.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

The use of DNA research in science

DNA sequencing is a laboratory technique that plays a crucial part in genetic research, enabling for precise determination of the order of nucleotides—adenine, guanine, thymine, and cytosine—that constitute the genetic code: unique data and guidelines on cell structure and functioning.

Discovering the coding sequences is immensely significant as the functions of specific genes can be determined this way. DNA sequencing is one of the fastest and cheapest methods of understanding the genotype.

The Human Genome Project (HGP) was launched in 1990, with the aim to determine the entire sequence of the human genome and create maps of all chromosomes. The project was sponsored by the US Department of Energy and the National Institutes of Health.

The results have proved that:

• there are around 30,000 human genes, which is less than previously estimated;

• 90% of a DNA strand and DNA strand is so‑called, non‑coding DNA—or contains information undiscovered as of yet;

• a genome is composed of more than 3 billion nucleotide pairs;

• some genetic information is coded RNA, which can carry out many biochemical reactions in organisms;

• our knowledge of the human genome is still poor; it does not resemble a simple recipe for protein formation but rather a complex computer program.

The knowledge obtained from the project will contribute to the development more effective methods of diagnosing genetic diseases and detecting the risk of their occurrence, and perhaps of preventing some of them. The HGP also enabled the link between specific DNA sequences and skills and abilities to be proved, and helped discover new techniques of determining genetic sequences.

Phylogenetics is a subset of evolutionary biology concerned with determining the origin of organisms. Until recently, the origins of and relationships between organisms, also those that are extinct, used to be determined chiefly based on their structural, developmental, and functional similarities. Now, with databases of genetic sequences of many organisms (RNA and DNA sequences) and protein structures as well as advanced bioinformatic tools, the process of describing the history of the living world is both easier and more reliable.

The results of molecular research can sometimes contradict data collected by the anatomists. Differences in evaluating the validity of results obtained using traditional and bioinformatic methods have caused a divide in the scientific community.

Currently the most popular opinion says that it is indeed molecular research that both provides the most reliable results and is easier to carry out. They also enable for more remains to be studied. Anatomists often need bones or other well‑preserved body parts, preferably intact, while just the DNA is enough for genetic testing, and can be acquired from small fragments that are useless to anatomists. The isolated DNA is sequenced, and the strands obtained this way are then compared with the DNA of other organisms. If the similarity is significant, the organisms are closely related. This method also allows for comparing RNA and proteins of different organisms.

A barcode is a common sight in a shop, where it serves to identify items in a database. An analogous function for organisms is performed by the genetic sequence, a unique identifier of every living creature. By determining the sequence of nucleotides, the species of any given specimen can be determined with absolute certainty. Ideas have already been proposed and first attempts made to create a library of the genetic code of all organisms.

The Barcode of Life Data System (BOLD) is already in place. In 2005, it comprised 33,000 barcodes (DNA markers) for 12,700 species. Within eight years, the database grew to more than 2.6 million markers for approximately 190,000 species. Each of them includes the species name, code sequence, date and place of finding the specimen, photographs and other information.

• Modern phylogenetics uses the methods of molecular biology.

• Every organism has its own unique identifier:the nucleotide sequence.