Topic: Human genetic diseases caused by chromosomal mutations

Target group

8th‑grade students of elementary school

Core curriculum

General aim of education

The student will find out which genetic diseases are caused by chromosomal mutations

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• distinguish between chromosomal mutations;

• give examples of human diseases caused by mutations.

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 explains the aim of the lesson and together with students determines the success criteria to be achieved.

Realization

• The teacher asks students to read the abstract themselves, paying particular attention to the illustrations.

• The lecturer presents an interactive illustration of „Chromosome mutations” and discusses the types of mutations leading to genetic diseases. The teacher also explains that they are rarer than diseases caused by gene mutations because the change in the number or structure of chromosomes usually leads to prenatal death or early childhood.

• The lecturer explains that the reason for the occurrence of chromosomal mutations is usually incorrect propagation of genetic material to gametes. The teacher introduces students to the concept of trisomy and chromosome monosomy.

• The teacher presents an illustration of „Selected genetic diseases caused by chromosomal mutations” and discusses examples of diseases in which an abnormal karyotype is observed. The instructor also informs that in a situation where a person with a genetic defect is fertile (eg Down's syndrome), it is not advisable to have children, due to the risk of inheriting the disease by children.

• The lecturer points out that the risk of errors during meiosis and the formation of chromosomal mutations increases with the age of the woman. For example, the appearance of Down syndrome or Edwards syndrome in a child is very strongly correlated with the mother's age.

• The teacher asks students to compare the effects of genetic diseases caused by mutations in autosomes with the effects of diseases caused by mutations in the sex chromosomes. Then he initiates a brainstorm during which the students try to explain the reason for this state of affairs.

Summary

• The teacher asks students to carry out the recommended interactive exercise themselves.

• 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.

Homework

• Listen to the abstract recording at home. Pay attention to pronunciation, accent and intonation. Learn to pronounce the words learned during the lesson.

• Using the website www.ndss.org create a poster informing what is Down syndrome, how to recognize it, how it is inherited. Look for organizations that help people with this disease.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Human genetic diseases caused by chromosomal mutations

Chromosomal mutations are changes in the structure of single chromosomes or the number of chromosomes in a cell. Such mutations are usually caused by an incorrect propagation of chromosomes to gametes during meiotic division. If chromosomes of one of the pairs do not separate but move together during meiosis, then one of the gametes receives both of these chromosomes after the division, and the other receives neither. Consequently, after fertilisation with such gametes, an individual referred to as trisomic may be formed, with three chromosomes of such pair (one from the correct gamete and two from the incorrect one), or monosomic, with only one chromosome from the pair.

Most embryos with chromosomal mutations die already at an early stage of development. Only a few chromosome mutations are not fatal, but they always cause serious genetic diseases.

• Chromosome mutations are changes in the number or structure of chromosomes.