Topic: DNA replication

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:

2. indicates the importance of the double helix structure in the DNA replication process; gives the importance of the DNA replication process.

General aim of education

You will learn how to reproduce genetic material in the cell

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• describe the structure of DNA;

• describe the relationship between DNA and gene;

• explain what the duplication of genetic information is and when it occurs.

Methods/techniques

• expository

  • talk.

• activating

  • discussion;

  • brainstorming.

• 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 the students whether they know how to divide the genetic material before the cell divisions discussed in previous classes. It also gives a hint to consider the purpose of recording genetic information in the form of two complementary threads. By working with the brainstorming method, students give their ideas and try to find the right answer.

• The teacher divides the students into an even number of groups (4, 6 or 8) and each of them gives half of the cut page with the sequence of nucleotides on one of the DNA strands. The task of each group is to add in the empty fields the appropriate sequence of complementary nucleotides, added on the second strand. After finishing the work, all groups compare their cards. The teacher explains that during the replication process, nucleotides are attached to each strand independently, but thanks to the principle of complementarity identical DNA molecules are created..

• 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 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.

• 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.

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

DNA replication

Each newly created cell must receive its own set of operating instructions, its own DNA. Therefore, before the division in the parent cell, the number of molecules of this acid must be doubled, i.e. replicated.

When replicating, the DNA molecules are unraveled. This is possible thanks to special enzymes, which „unzip” hydrogen bonds and cause the pairs of nitrogen bases to break. Then a new strand is added to each old strand according to the rule of complementarity. The adenine nucleotide belonging to one of the parent („old”) DNA strands forms a pair with the thymine nucleotide of the newly formed DNA molecule. The guanine nucleotide forms a pair with a nucleotide containing cytosine. In this way, as a result of replication, two daughter molecules of identical structure are formed from one parent DNA molecule. The daughter cell receives the DNA consisting of one old and one new strand. The replication process guarantees that each of the resulting daughter cells will receive the same genetic material as the parent cell.

• New DNA molecules arise as a result of replication. Replication occurs in the cell nucleus before the cell division.