Interrelationships

TEMPLATE FOR A UNIT OF TEACHER SUPPORT MATERIAL

Subject: Biology

Unit: 5

Form: S.4

Topic: Interrelationships

Introduction:

Earlier on in the course you learnt about the great diversity of living things and classified them into five kingdoms: - monera, protoctista, fungi, plantae, animalia Each type of organism lives where conditions are suitable for it. Such places are called habitats, For example, Tilapia lives in fresh waters, monkeys live in forests, papyrus is found in wetlands, Habitats constitute larger units called ecosystems, short for ecological systems like lakes, grassland, forests, swamps, seas. Ecosystems in turn constitute the biosphere – that is, the land water and thin mantle of air around the earth where organisms are found.

The non-living or physical factors of a place such as the type of soil, rock amount of water types of water, the temperature and air determine which organisms can live in a place. The living things depend on, and affect the quality of the non-living components of their habitats and ecosystems.

The living organisms in a given ecosystem interact with members of their own species as well as those of other species. Members of the same species may compete for space, oxygen and food. Plants depend on animals for carbon dioxide and dispersal. They use the carbon dioxide breathed out by animals for photosynthesis. Animals on the other hand depend on plants for oxygen, shelter, and food.

People depend on resources from the environment for their livelihood and development. They depend on plants and animals for food. They use plants as building materials, for crafts making, fuel and medicine. They use sand and clay for construction, lakes and rivers for transport.

Self-regulating systems exist and ensure balance of nature in the environment.

People, however, tend to interfere with this balance as they carry out various activities e.g. settlement, agriculture, mining, industry. These activities reduce the quantity of the resources. The wastes they produce may affect the quality of the environment, if they are not managed well. There is need to maintain the quality of the environment by using resources wisely in order to ensure the continuity of life and its diversity.

Sub-topic: Humans and Natural Environment

Brief description of sub-topic /introduction to sub-topic.

This unit aims at enabling students to

• Appreciate that people depend on natural resources for their livelihood and development.
• Develop the ability to use the resources wisely.
• Develop the ability to keep their environment clean and healthy.

Identify the human activities and practices in your localities that degrade the environment. The activities may include agriculture, fishing, settlement, and industry. The practices may also include deforestation, poor farming methods, uncontrolled fires, poor waste management, and poor mining methods etc. Take note also of the good practices and any other activities that conserve the environment.

Relate environmental degradation to human population growth. By analyzing the activities and their effects, you should be in position to suggest solutions to environmental problems. Appreciate the need for commitment and active participation in the conservation of the water, air, land, forests, wildlife and other natural resources around you.

Learn also about human activities and their effects in other parts of the country and the world. Learn also about conservation activities elsewhere and may be able to emulate some of them. In other words, you should be able to think globally and act locally.

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Time required (or hours): Minimum: 8 periods (5hrs 20 Mins)

Maximum:

Main content and concepts to emphasize.

Natural resources; Renewable and non-renewable resources; Human activities and their effect on the environment; exploitation; protection; preservation; conservation; sustainable development; waste disposal; waste management pollution; attempts being made to reduce pollution; active participation in conservation activities. Ozone layer, Global warming, Climate change

List items of teaching/learning materials:
(Worksheet, stimulus activity, experiments, items of evidence, statistics, texts, pictures, diagrams, graphs)

• Charts on human activities
• Charts on effects of human activities on environment e.g. eroded area, floods due to silting, gaping holes as a result of quarrying, dead fish on water due to oil spill, water covered with green mass of algae, etc.
• Chart on waste disposal.
• Work sheets for fieldwork.
• Animation of human activities and their effects on natural resources, conservation measures.
• Photographs showing poor and good waste management
• Photographs showing over grazing and its effects.
• Graphs showing changes in resources, changes in human population.
• Table (s) of statistics showing changes in resources, changes in human population.
• Text books

TEACHER’S GUIDE:

Include essential teacher information on separate pages: topic notes, learning objectives, organizational advice and tips, answers to student exercises, advice on assessment/evaluation, marking and exam preparation, suggested follow-up and extension work, useful textbook references and other resources)

TEACHING SYLLABUS

Topic 12: INTER- RELATIONSHIPS.

1. Food chains and food webs

Week 1

• Introducing basic concepts of an ecosystem and habitat.1 period.
• Food chains, food webs, producers, consumers and decomposers.
• 2 periods………………………………….
• Ecological pyramids: pyramid of numbers in an ecosystem…

1 period.

Week 2

• Ecological pyramids: pyramid of biomass, pyramid of energy in an ecosystem……………. 2 periods

1. Changes in population

• Definition, characteristics and patterns of population growth…..

1 period

• Carrying capacity………………….. 1 period

Week 3

• Factors limiting population growth………….. 2 periods
• Control of microbial growth…………………. 2 periods

Week 4.

• Predator – prey relationship…………………… 1 period

• Colonization and succession………………. 1 period
• Human population growth………………….. 1 period

1. Symbiosis (to include parasitism, mutualism and commensalisms)

• Characteristics and adaptation of parasites………… 2 periods

Week 5

• Feeding habits and host parasite balance………. 3 periods
• Methods of controlling parasites ………………….. 1 period

Week 6

• Methods of controlling parasites ( continued)……. 1 period
• Malaria and trypanasomiasis…………………. 2 periods
• Mutualism and commensalism……………….. 1 period

4. Humans and natural environment

Week 7

• Human inference with the natural environment ….. 2 periods
• Importance and conservation of natural resources…. 2 periods

Week 8

Importance and conservation of

• natural resources…. 2, periods
• Pollution and control ………………………………. 2 periods

N.B the work in this topic requires 32 periods. But – a number of areas are touched in other topics. If this topic is done last, the number of periods goes down tremendously.

(Quantitative sampling, parasitism, soil conservation would have been covered earlier)

Organizational advice and tips

• This sub-topic can be very well understood when students do field work.
• Identify suitable locations and resource persons around the school. Keep an inventory of resource persons.
• Lead students to the field. Follow them when leaving the field.
• Get permission from school and local authority where fieldwork is to be done.
• Take the necessary safety precautions e.g. need for gumboots, gloves e.t.c
• Field work is best done in groups
• Students must be prepared before going to the field. If possible, a preparation session should take place before the lesson involving fieldwork.
• Work sheets should be provided.
• Because there are many resources to be covered, different groups investigate a different resource or a different human activity. Reporting by groups to the whole class enables every student to learn about many human activities, their effects on the environment and conservation measures.
• Displaying reports on the notice board allows the students more time to learn the content.
• A stimulus activity at the beginning could be a short story comparing the past and present status of a resource and giving information on the methods of using the resource now and in the past. It can be a skit. Use ICT if possible.
• Carrying out investigations first enables students to get the concepts. They can then be introduced to national issues and later international ones.
• Give the students opportunities to suggest solutions and to participate in conservation activities.
• Encourage students to engage in follow up activities and extension work to enable them to learn more and also to apply what they have learnt to real life situations.
• Encourage students to read about environmental issues in the newspapers and form other sources.
• Ensure that in this topic students learn about the environment in the environment and for the environment
• Learning about what happens in other parts of the world is easier to handle after dealing with their own locality.

Pre-requisite knowledge

• Feeding relationships among organism in habitats and ecosystems.
• Inter dependency between organisms for shelter, medicine, food, etc
• Soil conservation: meaning, need for, methods
• Natural resources of Uganda
• Population (human) growth rate
• Environmental hazards and diseases.

STIMULUS ACTIVITIES

Activity 1

Skit, short story (either live PowerPoint or on CD) about disappearing forests, Status was okay in the past, people harvested the parts of plants they needed, e.g. fallen dry branches for fire wood, building poles, leaves of medical plant, fruits.

Today people fell trees indiscriminately to get firewood, charcoal, timber. They even cut down medicinal plants!!

Present status

Forests are gone; dry seasons are longer, shortage of firewood, building poles, fruits and medicinal herbs. Monkeys that lived in forests now feed on crops.

Conservation

Community meeting in which community diagnosis is carried out to identify problems, Solutions are suggested and the best solutions adopted for conservation e.g. aforestation, agro forestry, use of alternative materials for fuel , building.

Activity 2

Quotation by MYM (Martin Yiga Matovu.) Nov. 1994 in an EE workshop.

“What you do

To the environment today

Spells out what the Environment

Will do to you Tomorrow;

What you Don’t Do

For the Environment Today

Determines what you can’t Do

For your self Tomorrow.

That’s the Only

Just Tit for Tat I know”

Question:

What do you learn from the skit and the quotation?

LEARNERS’ ACTIVITY (during the lesson)

Questions

1. Name 5 natural resources in your country and state their uses

Resource	Uses
1
2
3
4
5

2.Name any three activities that degrade the environment in your country and state how

Examples of answers to the learner’s activity

1.

Resource	Use(s)
1. Forest	Source of timber, medicine, firewood, building poles, fruits used as food Involved in formation of conventional rain thus stabilizing the climate.
2. Lakes	Source of fish, transport
3. Soil	Used for agriculture and settlement
4.
5.

2.

• Overstocking (i.e. putting more animals on a piece of land that is too small to support them) results in overgrazing which in turn leads to soil erosion
• Deforestation leads to shortage of timber, firewood, fruits, medicinal plants, building poles
• Over harvesting wetlands e.g. over fishing, cutting down too much papyrus degrades the wetland, causing shortages of fish, materials for crafts making, clean water

Suggested follow-up and extension work

1. Set students tasks that require them to investigate community approaches to, and indigenous knowledge on environmental management practices.
2. Guide students to form clubs or associations to put into practice environment management projects and encourage their adoption by communities.
3. Develop an Environmental Education (EE) programme in the school to be able to

• benefit from the learning materials being produced by their peers in other schools
• understand the EE objectives

REFERENCE BOOKS AND OTHER RESOURCES

• Macmillan Secondary Biology. Pp 376 – 406
• D.G Mackean (2003): Introduction to Biology pp 224 – 233
• Biology for Life pp 94 – 101
• R.H Stone, A.B Cozens (1994): New Biology for Tropical Schools pp 300 – 304; 317 – 318
• Bola Maxwell – Ojo (1982): Modern Tropical Biology pp 222 – 225

NB. (A lot of information on this topic can be obtained from NEMA. – includes leaflets, charts, books etc.

NEMA: state of the Environment Report for Uganda. (Published every two years)

WORK SHEETS

Work Sheet 1 FOR FIELDWORK

Quarrying site

Date…………………………

Location……………………

Name(s) of student…………………..

Find out the following at the site by asking the people there.

1. Who are doing the quarrying/mining?

………………………………………………………………………………

2. What are they mining?

………………………………………………………………………………

3. Why are they mining?

………………………………………………………………………………

4. When did they start?

………………………………………………………………………………

5. What methods do they use?

………………………………………………………………………………

6. What effect does the mining have on the
   1. Landscape……………………………………………………..
   2. The natural resource they are mining?…………………………………………………………
   3. The people around and their animals?………………………………………………………….
7. What is done to the holes/pits that are formed?……………………..
8. What problems arise as a result of mining?……………………………………………………………………………………
9. What practices do the people around carry out solve those problems

……………………………………………………………………………….

10. Are there alternative materials that can be used?……………………….
11. Write a report. Present it to the class, and display it on the notice board for all to read in their free time. Where necessary class can write to relevant authority for intervention e.g. school authority, local government, District environment officer, NEMA.

……………………………………………………………………………..

Worksheet 2

(e.g. Forest. wetland/grassland/lake/farming/charcoal production)

Date:………………….

Location:…………………..

Name(s) of students…………………………….

Collect the information by observing, learning from a resource person or interviewing the people around. Some of the people you interview should have lived in the area for a long time.

1. What human activities are carried out on the named ecosystem?……………………………………………………..
2. Who carry them out?……………………………………………
3. Why are they carried out?………………………………………
4. What methods are used?……………………………………….
5. What effect do the methods and activities have on the ecosystem?……………………………………………………..
6. What methods were used, say, 50 years ago?…………………………………………………………….
7. What effect did they have on the ecosystem?…………………………………………………….
8. Are any wastes produced during these activities? If so, list them.

………………………………………………………………………

………………………………………………………………………

9. How are they disposed of? ……………………………………

………………………………………………………………….

10. What alternative materials can be used?…………………………………………………………….
11. What conservation measures are being taken?…………………………………………………………..
12. Compile a group report. Present it to the class. Display the report on the class notice board for all to read in their free time. Where necessary inform the relevant authority for intervention e.g. school authority, local government, District environment officer, NEMA.

Example of table of results.

Findings can be summarized as shown below: -

Resource	Benefits	Status	Environmental threats	Possible solutions.
Forest	Fuel, food, medicine, Building materials. Home for animals.	Abundant? Rare? Threatened? Endangered?	- Land fragmentation - Population growth. - Agriculture. - Uncontrolled tree felling.	- Alternative fuel. - Energy saving stoves. - Alternative building material. - Education /sensitization. - Law enforcement.
Wetland
Grassland
e.t.c

SAMPLE QUESTIONS

Section A: Objective Questions

1. Which of the following is most unlikely to cause water pollution?
   1. Domestic waste
   2. Industry effluent
   3. Fertilizers
   4. Gaseous factory waste
2. The wise use natural resources that can lead to sustainable development is
   1. Protection.
   2. Exploitation
   3. Conservation
   4. Preservation
3. Select the natural resources that is non-renewable
   1. Forests
   2. Petroleum
   3. Grassland
   4. Wetland.

Section B: Structured Question

1.

Parked vehicles People washing vehicles very close to the Litter e.g. polythene lake side Dirty soapy water going into lake water

The above photograph shows a human activity going on by a lake. Study it carefully and answer the questions that follow.

1. Identify the human activity……………………………………

(1 mark)

2. What problems might the activity named in above cause to the lake

…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

(6 marks)

3. What can be done to solve the problems and ensure that the lake remains a healthy ecosystem? ………………………………………………………………………………………………………………………………………………………………………………………………………………………………

(3 marks)

Section C: Essay/Long answer Question

1. a) What is meant by environmental degradation? (2 marks)

b) Describe how human activities lead to degradation of wetlands

(7 marks)

c) How does the degradation of wetlands affect people? (4 marks)

d) Suggest solutions to ensure the quality of wetlands. (3 marks)

ANSWERS TO SAMPLE QUESTIONS

Section A: Objective questions

1. D
2. C
3. B

Section B: Structured question

1. a) Washing vehicles

b) Dirty water, which has soap, dirt and oil, goes into the lake. This may cause

the death of fish and other organisms. The dirty water changes the colour of the water. Less light penetrates the water. Therefore, the algae and water plants get less light and make less food. This means the fish and other animals will have less food. The productivity of that part of the lake falls

(c)

• Educate the people and carry out awareness activities so the people learn the uses of the lake and the effects of their activities on the lake
• Advise the people to carry out activities a reasonable distance away from the lake. These distances are stipulated.
• Laws should be enforced

Section C: Essay/long answer question

1.

1. Reducing or lowering the quality of the environment in one or more of the following ways:

• The variety of its elements are reduced or lost
• The quality of its elements is reduced or lost
• Its productivity is reduced or lost
• The stability of its elements is reduced or lost.

b)

• Practicing agriculture very close or at the edge of the wetland and in the wetland leads to water pollution. Agrochemicals and animal droppings get into the water.
• Growing plants there may lead to drying up of the wetland
• Over fishing leads to decrease in types and quantities of fish.
• Over harvesting of material for building, crafts making removes the natural home of some animals e.g. sitatunga
• Release of untreated factory effluents makes conditions unfavorable for the biodiversity of the wetland
• Construction in wetlands obstructs water movement.

c)

• The water becomes unfit for human consumption as well as use for domestic animals.
• People would get less food in form of fish, meat and plant food.
• If heavy metals are deposited in the wetland, they will get into the people through the food chain e.g. when they eat yams grown in the wetland.
• Obstruction to water movement can lead to flooding of nearby areas.

d)

• Education and public awareness
• Enforce laws
• Regulate the rate at which resources in the wetland are harvested
• Treatment of factory waste before it released into the wetland.

GLOSSARY

Conservation:

Wise use of natural resources such that excessive degradation and impoverishment of the environment is avoidable. It includes searching for alternative food and fuel when these become endangered, awareness of pollution, maintenance and preservation of natural habitats and creation of new ones

Degradation:

Reduction or lowering of the quality and usually quantity of a resource. It is caused by human activities.

• Variety of elements on the resource are lost or reduced
• Quality of elements in the resource are reduced or lost
• Productivity is reduced or lost
• Stability of elements of the environment are reduced or lost.

Preservation;

Not using a resource. This could be for some time e.g. when there is need to stop a species from becoming extinct, an ecosystem from becoming depleted. The resource is allowed to build up again.

Resource:

Anything of utility to humans. Some resources are natural e.g. water, air, land, biodiversity.Other resources are built or man-made e.g. buildings, roads

Pollution:

Undesirable change in the physical, chemical or biological characteristics of the natural environment caused by human activities. It may be harmful to people and other living things. Pollution can affect soil, water (rivers, seas, lakes) or air.

Pollutant: Substance/something that causes pollution when added to the environment up to a certain level. Types of pollutants: - non- biodegradable ones (e.g. heavy metals in industrial effluents), biodegradable ones (e.g. sewage)

Examples of pollutants: - noise, heat released into lakes or rivers, radioactive material, increasing level of carbon dioxide, chlorofluorocarbons

Bio-degradable:

Decomposable. Refers to materials that can be broken down in the metabolism of organisms. They are usually broken down to simple useful materials. E.g. Organic wastes.

Non-biodegradable:

Non- decomposable. Refers to materials that cannot be broken down. These tend to accumulate in the environment e.g. some forms of polythene.

Reusing

Putting waste to some other use e.g. tins can be used for storage of food like sugar, flour or as flowerpots. Polythene can be made into balls or ropes used as lines for drying clothes.

Re-cycling:

Involves breaking down waste into something that is used to make something else. E.g. polythene, glass, can be melted and made into other things.

Global warming: Rise in surface of the earth ‘s temperature due to (1) increase in carbon dioxide, which forms a blanket above the earth that prevents heat from moving up 2 Green house gases e.g. CFC’s that erode the ozone layer, more heat reaches the earth’s surface.

Climate change: Refers to the long-term change of one or more climatic elements from previously accepted long-term mean value. The main variable of climate change is temperature.

Climate change can affect human health and well being e.g. it can adversely affect the availability of fresh water the ability to produce food, the distribution and seasonal transmission of vector-borne diseases like malaria.

(Reference: State of environment report for Uganda, 2004/2005 page 50)

Ozone layer: A layer of the earth’s atmosphere, 15 –50 km above the earth’s surface. It absorbs most of the sun’s ultraviolet radiation. It protects living organisms from ultraviolet rays.