Topic: Non‑inherited variation

Target group

8th‑grade students of elementary school

Core curriculum

General requirements

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

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

Specific requirements

VIII. Threats to biodiversity. Pupil:

1. presents the essence of biodiversity.

General aim of education

The student will learn the main causes of non‑hereditary variation

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• to tell the difference between and provide examples of inherited and non‑inherited variation.

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.

• The teacher initiates a conversation introducing the topic.

  • What do you know about ...?

  • Have you ever met ...?

Realization

• The teacher introduces the concept of non‑inherited variability and explains that it results from the action of external (environmental) factors on a given organism, causing phenotypic diversity of individual individuals of one population.

• Using the interactive illustration titled „Non‑inherited variability” the teacher presents and discusses examples of the influence of selected factors on animal and plant organisms.

• The teacher draws students' attention to the relationship of environmental factors with lifestyle diseases such as diabetes and hypertension, initiating a brief discussion on the prevention of these diseases.

• Working in groups and using various sources, students search for non‑inherited varieties of plant or animal organisms other than those mentioned so far during the lesson. Then each group presents the results of their own work, discussing the chosen example.

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

Summary

• At the end of the class, the teacher asks the students questions:

  • What did you find important and interesting in class?

  • What was easy and what was difficult?

  • How can you use the knowledge and skills you have gained today?

  Willing/selected students summarize the lesson.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Non‑inherited variation

Apart from genetic variation, there is also non‑inherited variation i.e. environmental variation. It accounts for all the changes in the organism’s phenotype during its lifespan that are caused by various external factors. These traits are not passed on to the offspring. One example of environmental variation is the heterophylly of the arrowhead plant (Sagittaria sagittifolia). The shape of its leaves is determined by its surroundings. The leaves of a fully submerged arrowhead are ribbon‑like, and those that grow above the water are arrowhead‑shaped.

When planting the seeds of an arrowhead plant with ribbon‑like leaves, the leaves of new generations will be ribbon‑shaped, oval‑shaped, arrow‑shaped or in all shapes, depending on the depth of the water reservoir.

• Non‑inherited (environmental) variation accounts for all the changes in the organism’s phenotype during its lifespan that are caused by various external factors.