Ecology · SHS1 Biology

Lesson notes

Learning Objectives

Indicator: 1.3.2.LI.1 - Distinguish between the direct counting, gut examination and radioactive/tracer methods of determining the flow of energy in an ecosystem.

By the end of the lesson, learners can:

Describe how direct counting is used to determine energy flow in an ecosystem, including its basic procedure and one example of when it is practical.
Explain the gut examination method, stating what scientists look for in animal stomach contents and what information this reveals about energy transfer.
Describe the radioactive/tracer method, including how a tracer substance is used to follow the movement of energy through a food chain.
Compare the three methods by listing at least one advantage and one limitation of each method.
Select the most appropriate method for a given ecological scenario and justify the choice with a valid reason.

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Curriculum details

Strand: Diversity of Living and Thins and Their Environmnet (Strand 3)
Sub-strand: Ecology (3.2)
Content standard: 1.3.2.CS.4 - Demonstrate knowledge and understanding of methods of determining energy flow in an ecosystem. 1.3.2.LO.1 Apply the knowledge of ecological terms to describe the concept of ecology. 1.3.2.LO.2 Explain how the living and non-living components of the environment interact to ensure the sustenance of life. 1.3.2.LO.3 Explain and show how various simple ecological tools can be used to estimate the population of species in a given habitat. 1.3.2.LO.4 3.2.4.1: Explain the relevance of direct counting, gut examination and radioactive/tracer methods of determining the flow of energy in an ecosystem. 1.3.2.LO.5 Explain the methods of determining and comparing the efficiency of energy flow in pyramids of numbers, biomass and energy.
Indicator: 1.3.2.LI.1 - Distinguish between the direct counting, gut examination and radioactive/tracer methods of determining the flow of energy in an ecosystem.
Suggested placement: Semester 2, Week 9 (Week 29 of the year)
Our suggestion, laid out in curriculum order across three terms of twelve weeks. NaCCA does not fix the week, so follow your school's scheme of learning.
Curriculum reference: NaCCA curriculum document, p. 53

Exemplars (from the NaCCA curriculum)

Inquiry-Based Learning: learners in small mixed-ability groups research or listen to presentations on the various methods of determining energy flow in an ecosystem to be better informed, and discuss these in a class presentation: by conducting an inquiry-based research, learners become self-initiating and develop self-confidence as they also learn to work in a team. Learners work together to build selfconfidence. Learners respect the contributions of other members, and present their opinions in candid but humble and respectful ways.
Task-Based Learning: learners in all-inclusive groups create a chart on the advantages and disadvantages of the various methods of determination of energy flow and demonstrate their charts in class presentations: as learners work together, they build team-spirit and learn to support one another socially and emotionally; each member in the group become self-initiating and develop confidence as each member plays a specific role in the group.
Teaching and Learning Materials:
- * Computer/projectors/TV/smart phone * Pen drive
- and GESI
- * Pictures * Textbooks
- * Specimens of habitats
- organisms in different
Assessment (1.3.2.AS.1). The document marks these depth-of-knowledge levels for this indicator: Level 1 Recall; Level 2 Skills of conceptual understanding; Level 3 Strategic reasoning.