Topic: At the lake

Target group

4th‑grade students of elementary school

Core curriculum

Grade IV
VI. The natural environment of the immediate area. Pupil:
12) defines living conditions in water (sunshine, oxygen content, water resistance) and indicates the adaptation of organisms (eg fish) to the living environment;
13) recognizes and names organisms living in water.

General aim of education

Students recognize selected organisms living in the lake and describe the adaptations of their external construction and life activities to the environment.

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• distinguish in the lake the coastal zone, water depth and bottom;

• describe the conditions prevailing in different zones of the lake;

• assess the living conditions in each of the lake's zones;

• recognize selected plants and animals living in the lake.

Methods/techniques

• activating

  • discussion.

• expository

  • talk.

• 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;

• magnifying glass;

• sheets of gray paper;

• crayons;

• colored markers;

• specimens of coastal plants: reeds, water batons, calamus;

• specimens of water snails: creek and marshmallow;

• live cyclops and daphnia.

Lesson plan overview

Before classes

• The teacher asks the chosen student or students to get acquainted with the abstract material and to prepare the illustrative material for the lesson.

Introduction

• The teacher gives the topic, the goals of the lesson in a language understandable for the student, and the criteria of success.

• Selected students present the illustrative material prepared by them before the lesson.
  The teacher encourages the class to ask questions to the presenters, e.g.

  • Why did you choose such examples?

  • What does this photo involve?

  • What this illustration is talking about

  • Why is this scheme important?

  • What is the graphics to tell us about?

• The teacher asks the chosen student to characterize the conditions prevailing in the water, affecting the life of aquatic organisms.

Realization

• The teacher asks the pupils to read the fragment Fri „Plants and animals of lakes”. Students present species diversity of lakes.

• The teacher divides the class into groups. Each receives a sheet of gray paper, crayons, colored markers and signed specimens of coastal plants (specimens of reed, stick, calamus) and water snails (specimens of cove and pond marshmallow, or possibly their shells). The students' task is to recognize the differences and similarities between plant species and between species of snails, and then to illustrate them on the poster. After completing the task, group representatives present the results of teamwork.

• Each group receives live specimens of daphnia and waterflies in a container of water and magnifying glass. Students observe the behavior of these organisms when the location of the water tank changes: they determine whether they are subjected to water movement. Together with the teacher they define the concept of plankton.

• The teacher instructs the pupils to read the section „Living conditions in the lake” and then displays the interactive illustration. Pupils discuss individual water zones and adaptation of selected animals to live in specific areas of the lake. The teacher complements students' statements, corrects possible mistakes.

Summary

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

Homework

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

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

At the lake

A lake is an inland body of water, which is formed in a natural depression filled with surface or underground water. It is inhabited in almost its entirety by organisms. The waters of a lake can be divided into three main zones: littoral, pelagic and benthic.

The littoral zone is so shallow that sunlight reaches the bottom. Due to this, plants can grow there. The water is well oxygenated and permanently supplied with minerals, which drift down with rain water. In this zone, however, fluctuations in the lake's water levels can be most strongly felt, along with rippling and pollution reaching the lake from land. Large temperature changes occur here throughout the day and over the course of the year.

The pelagic zone denotes the open expanse of water away from the banks, which does not have contact with the bottom. It reaches such a depth that the Sun's rays still penetrate it, and so its depth is dependent on the water's transparency. Living conditions for organisms quickly worsen as the depth increases in this zone, as the amount of light and the oxygen content of the water decrease, and the water temperature falls.

The benthic zone denotes the area at the bottom of the lake, where sunlight does not reach, in addition to the water directly neighbouring the bottom, to which sunlight also does not reach. In deep lakes, the water at the bottom has a temperature of +4⁰C all year round. Here, there is very little oxygen dissolved in the water, and periodically, there may be none at all.

A lot of plants and animals live in lakes. Their distribution, however, is very uneven. The vast majority live in the littoral zone, significantly less in the pelagic zone and the least in the benthic zone.

Plants growing in the littoral zone grow out of the shallow water, and sometimes grow on the land right next to the bank in places which are flooded by waves. These are often reeds, bulrushes and calamus. Numerous animals live here, which are strongly linked to both the water and the land, such as frogs and other amphibians, marsh turtles, grass snakes and waterfowl and wading birds (for example ducks and geese, grebes, herons, storks, cormorants and many more). Plants with floating leaves grow a little further from the banks, for example the yellow water‑lily and the white nenuphar, and even further hornworts and waterweeds, as well as common duckweed, which floats on the water. Insect larvae live among the plants (for example the larvae of dragonflies and mosquitos), snails, leeches, crabs, clams and fish (for example sticklebacks, roaches, tench, perch and pike).

In the pelagic zone, plants are almost exclusively represented by plant plankton. Animals which occur include zooplankton and a few types of fish, for example bleak and zander.

Plants cannot live in the benthic zone because of the lack of light, and the animals feed on organic remains which fall from above, or smaller animals. Small annelids live here, the larvae of certain insects, clams and fish looking for food in the mud at the bottom (catfish, lavaret and carp).

• We divide a lake into three zones in relation to the conditions found there: littoral, pelagic and benthic.

• In the littoral zone, the water is the warmest, there is the most oxygen, and sunlight reaches the very bottom; the most plants and animals occur here.

• In the pelagic zone, light reaches the water, but there are few plants and little organic material; plankton and a few animals occur here.

• In the depths near the bottom, it is dark, cool and there is little oxygen; there are almost no plants here, and animals feed on remains falling from other zones, organic material or other animals.