Topic: Heterotrophy, autotrophy

Author: Elżbieta Szedzianis

Target group

5th grade students of an eight‑year elementary school.

Core curriculum

Lesson plan overview (Process)

The students talk about the notion of autotrophy and heterotrophy, as well as give examples of organisms which are autotrophs and heterotrophs.

Key Success Criteria

• you will explain which organisms are the autotrophs, and which ones are the heterotrophs;

• you will talk about the ingredients that are included in food and describe their role;

• you will create a model of a food chain that consists of four elements.

Key Competences

• communicating in the mother tongue;

• communicating in a foreign language;

• mathematical competence and basic competences in science and technology;

• digital competence;

• learning to learn;

• social and civic competences.

Methods/Forms of work

A talk, didactic game, mixed sentences text, work with film, work with text, workshop method.

Individual work and work in groups.

Teaching measures

• abstract;

• interactive or traditional whiteboard;

• tablets/computers;

• mixed sentences text;

• paper strips with names of organisms that create food chains;

• crayons;

• glue.

Lesson plan overview (Process)

Introduction

1. The teacher presents the topic of this lesson and the key success criteria, as well as the planned outline of the class.

2. The teacher presents two pictures: of a plant and of a child eating a hamburger (with lettuce, onion and tomato). He announces that a plant is an autotroph, whereas a child is a heterotroph. He writes both notions on the board and invites the students to play. He explains the rules: each person may gain 1 point for giving the correct example of an organism that belongs to one of the two categories, and another 2 points for defining the group which a mentioned organism belongs to. The students start playing and writing down their propositions on the board. Incorrect or repeated examples are rejected by the teacher, which means the students who submitted them do not get a point. After running out of ideas, the students select a winner, whereas the teacher asks them to explain the difference between the autotrophs and the heterotrophs.

Realization

1. The students write down the definitions of autotrophy and heterotrophy in their notebooks, using the abstract when needed.

2. The teacher asks the students to explain, why organisms feed. Next, he talks about nutrients and their meaning, while students prepare a note about it.

3. The students complete the interactive exercise.

4. The teacher divides the students into groups. Each group receives a mixed sentences text prepared by the teacher on the basis of the abstract. (Attachment  No.1.) After completing the task, the teacher presents the correct order of sentences on the interactive whiteboard.

5. The teacher shows a movie. He asks the students to comment on the content of the movie and propose a title for it.

6. Students receive paper strips with names of organisms that create food chains
   . The teacher asks them to colour the autotroph strip green, and then to arrange the remaining strips in order that reflects the relations that happen between them, answering the question “who eats whom?”. The students glue those strips together creating a food chain.

Summary

1. The teacher asks chosen students the following questions:

• Are you an autotroph or a heterotroph?

• What nutrients do we receive in food?

• How does our body use nutrients?

2. The teacher asks the students to complete the sentecenes: “During this lesson, I found out that....”.

Optional homework

Students prepare models of food chains that consist of four selected organisms.

Attachment No. 1.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Heterotrophy, autotrophy

Food of heterotrophs consists of organic compounds produced by other organisms. Animals, fungi, most of the bacteria and some protists are heterotrophs. Herbivore animals eat entire plants or fragments of plants. Carnivores include predators, which hunt other organisms and scavengers – species which do not hunt, but feed on the dead bodies of animals, e.g. remains left by predators. Omnivores are animals eating both plants and animals. Parasites absorb food from the bodies of representatives of other species, called hosts. Some parasites live on the bodies of their hosts, whereas others live inside them. It is in the interests of parasites that the host should live as long as possible, providing them with access to nutrients. Plants can also be parasites.

Saprobes feed on dead organic matter, mainly organic remains in forest floor, soil or river mud.

Food absorbed by the organism must nourish every cell of its body. That is why large portions of food are first crushed, then decomposed into simple compounds, as that is the only form in which they can be absorbed into the cells. The process of decomposition of larger portions of food is called digestion and happens in participation of digestive enzymes. These special proteins speed up the decomposition of complex compounds into simpler compounds.

Internal digestion takes place inside the body in the digestive system, like in the case of rabbits. External digestion takes place outside the organism, as in the case of champignon.

Autotrophs are green plants and other organisms that have a green pigment that is able to absorb light (e.g. algae and Cyanobacteria). Autotrophs produce necessary organic compounds on their own, during photosynthesis – they absorb water and carbon dioxide from the environment, and, in the presence of the light, they transform it into glucose. For autotrophs, glucose is a source of energy (food). In plants, glucose is produced mainly in leaves and must be transported into all the cells which it nourishes.

• Feeding is based on providing organisms with matter needed to build cells and energy necessary to perform life functions.

• Because of the way how an organism feeds, we divide them into autotrophs and heterotrophs.

• Autotrophs synthesize organic compounds on their own, whereas heterotrophs use organic compounds produced by autotrophs or other heterotrophs.

• In order to move you need energy from the food.