MINISTRY OF PRIMARY AND SECONDARY EDUCATION

COMPONENT E

LEARNER CALA GUIDE

LEARNING AREA : COMBINED SCIENCE

LEVEL : FORM 4

SYLLABUS TOPIC. : CELLS AND LEVELS OF ORGANIZATION (ECOSYSTEM)

SYLABUS SUBTOPIC. : FOOD CHAIN AND FOOD WEBS

CALA TITLE. : COMPONENTS OF AN ECOSYSTEM

CALA TYPE : RESEARCH, PEN AND PAPER

COMPETENCIES : PROBLEM SOLVING CREATIVE THINKING AND DECISION MAKING

BACKGROUND. : It has been noted with concern that gardens are sprayed with

Non - selective herbicides which then disturbs the flow of energy in the

Ecosystem.

The cala consists of 4 parts, Part A, B, C and D.

PART A : Record all living organisms found in your home or school garden.

PART B : construct a food web from all the living organisms in the garden.
PART C : Fish out any 3 food chain from the food web.

PART D : Propose, using any one of the food chains effects likely to be encountered when

Each organism is destroyed.

You are required to respond to all parts.

CALA TIPS: You may consider the following

i) Food chain starts with a producer.

ii) Some living organisms are found in the soil.

iii) Standard food chain has at least 3 living organisms.

COMPONENT E

LEARNING AREA : COMBINED SCIENCE

LEVEL : FORM 4

SYLLABUS TOPIC : ECOSYSTEM

SYLLABUS SUBTOPIC : FOOD CHAIN AND FOOD WEBS

CALA TITLE : COMPONENTS OF AN ECOSYSTEM

CALA TYPE : RESEARCH, PEN AND PAPER

COMPETENCIES : PROBLEM SOLVING, CREATIVE THINKING AND DECISION MAKING

BACKGROUND : It has been noted with concern that gardens are sprayed with

Non - selective herbicides which then disturbs the flow of energy in

The ecosystem.

DIMENSIONS TO BE ASSESSED

PART A

A. 1 Evidence of knowledge of what a living organism is. [1]

A.2 Evidence of investigating several living organisms. [7](1 mark for each organism)

A.3 Skills applied in identifying living organisms in the soil. [2] (1 mark for each method

PART B

B.1 Correct positioning of levels in the web. [4](1 mark for every trophic level)
B.2 constructing a food web with at least 7 characteristics. [6](1 mark for each arrows of prey)

PART C

C.1 Construction of a food chain with at least 3 trophic levels [4].

C.2 Fishing out all required 3 food chains. [2 ×3]

PART D

C.3 Application of critical thinking in explaining effects of destruction of any 3 components of a single food chain. [2 ×3] 2 marks for each
organism explained.

OBJECTIVES

By the end of the Cala learners should be able to:

1. Show skills of observations.

2. Express competencies of critical thinking in posing solutions to destroying pests.

3. Show competence of decision making and creative thinking in construction of food webs and chain.

CALA ASSESSMENT PROCEDURE

The work will be assessed basing on:

1 .Evidence of identifying at least 7 components in the garden area.

2. Constructing of a correct food web with all components recorded.

3. Correct positioning of trophic level in food chain and web.

4. Neatness of the write up.

CALA TIPS

You may consider the following:

ii) Food chain starts with a producer.

iiii) Standard food chain has at least 3 living organisms.

LEARNER CALA GUIDE

COMPONENT :E

LEARNING AREA : COMBINED SCIENCE

LEVEL : FORM 4

SYLLABUS TOPIC : ECOSYSTEMS

SYLLABUS SUBTOPICS : FOOD CHAIN AND WEBS

CALA TITLE : COMPONENTS OF AN ECOSYSTEM

CALA TYPE : RESEARCH, PEN AND PAPER

COMPETENCIES : PROBLEM SOLVING, CREATIVE THINKING AND DECISION MAKING

That gardens are sprayed with non- selective herbicides which then

Disturbs the flow or energy in the ecosystem.

DESCRIPTION

This CALA consists of 4 parts ,A ,B, C and D .You are required to attempt all the questions .The CALA will be marked out of 35 .

PART A

Record the names of all living organisms found in your home or school garden [10]

PART B

Draw a food web from all the living organisms in the garden [10]

PART C

Fish out any 3 food chains from the web. [10]

PART D

Propose, using any one of the food chains, effects likely to be encountered when each organism is destroyed. [5]
HOW YOU WILL BE ASSESSED

PART A

Marks will be awarded as follows

- Evidence of knowledge of what a living organisms is. [1]

-Evidence of investigation several organisms (stating at least 7 living organisms) [7]

-Application of appropriate schools in tracing some living organisms [2]

PART B

-Correct positioning of a trophic level in the food web. [3]

- Showing at least 7 energy flow arrows [7]

PART C

-Showing at least 3 trophic level in the food chain. [4]

PART D

-Selecting 1 food chain. [1]

-Application of critical thinking in explaining the effects of destroying each of the organisms in the food chains. [5]

CALA TIPS

You may consider the following:

i) Some living organisms are found in the soil.

ii) Food chain starts with a producer

iii)Standard food chain has at least 3 living organisms.

ACHIEVEMENTS STANDARDS

DIMENSIO EXCELLE MAR GOO MARK SATISFACTOR MARK UNSATISFACTOR MARK

A 9 – 10 6-8 4-5 2-3

C 9 – 10 7 - 10 5 -6 3- 4

D 5–6 4 3 2