Topic: Lineage and family tree

Target group

8th‑grade students of elementary school

Core curriculum

General requirements

I. Knowledge of biological diversity and basic biological phenomena and processes. Student:

2. explains biological phenomena and processes occurring in selected organisms and in the environment.

Specific requirements

V. Genetics. Student:

11. gives examples of human genetic diseases determined by mutations (cystic fibrosis, phenylketonuria, Down's syndrome).

General aim of education

Students explain how to track the inheritance of a selected trait in a family using a family tree.

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• describe the inheritance of selected traits in humans.

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

• The teacher defines the concept of family tree and explains that the family tree may be useful, inter alia, in determining the probability of the birth of a child suffering from a genetically determined disease.

• The teacher presents and discusses the interactive illustration. He explains that the easiest way on the basis of the family tree to determine the inheritance of these diseases, which are caused by dominant alleles (eg Huntington's chorea, some types of dwarfism and polyps of the large intestine). We observe the inheritance of the disease from generation to generation and its occurrence in all persons who inherited a defective, usually created by mutation, copy of a given gene. The teacher also explains that diseases caused by recessive genes are more difficult to predict. Such diseases include, but are not limited to, muscovascular disease, phenylketonuria or congenital cataract. People with one defective and one correct copy of the gene are healthy in this case. The disease is revealed only when two people with a defective copy of the gene have offspring. All children who inherit recessive allele from both parents will be sick.

• The teacher informs that if in someone's family there were cases of genetically determined diseases or future parents are related, it is advisable to perform special tests that will determine the risk of disease in their offspring.

• The teacher instructs the pupils to make each one of them draw a family tree of his own family and to trace through it the inheritance of the chosen feature (eg hair color, blood group). Then it indicates people who present the effects of their work on the class forum.

• Students, working alone or in pairs, perform tasks indicated by the teacher.

• Students, working individually or in pairs, carry out interactive exercises to check and consolidate knowledge learned during the lesson. Selected people discuss the correct solutions for interactive exercises. The teacher completes or corrects the statements of the proteges.

Summary

• Students ask questions, ask for additional explanations and complete the notes.

Homework

• Do an interview in your family, try to find out if there have been cases of genetic diseases.

• Those interested can create a note about the selected genetic disease.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Lineage and family tree

The inheritance of selected traits, e.g. blood groups, can be represented in subsequent generations using a family tree. It is a schematic record of the way inheritance of a given feature within a related group of people. In order to create such a tree, it is necessary to determine who showed the trait we were interested in in particular generations and who inherited it. After saving the tree, we can determine the phenotypes and genotypes of individual family members and the probability of the appearance of the examined feature in subsequent generations.

Huntington's disease is caused by mutation of a single gene in chromosome 4. The mutant gene is dominant. It creates a protein with toxic properties that is deposited in nerve cells and causes them to die. The disease consists of progressive dementia and is usually manifested after the age of 35. Usually, the holders of the defective gene already have offspring. Statistically, half of the offspring of a person with a defective allele will inherit this disease.

• The inheritance of selected traits, e.g. blood groups, can be represented in subsequent generations using a family tree.