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Natural sciences

Grade 8


Module 29


The previous learning units focused on the survival strategies of organisms living on planet EARTH .

We know that the organisms and their habitats together make up the earth’s variety (biodiversity) and that nature is maintained in perfect balance because of this BIODIVERSITY .

There are 250 000 higher species of plants, 19 000 species of fish and 10 000 species of reptiles. Many more species of insects have been recorded. This wealth of life forms ensures that:

  • there is an atmosphere that has the right combination and balance for our survival;
  • the soil remains fertile for new plants to grow so that we and other animals will always have food;
  • water is re-circulated.

South Africa is the only country in the world that has a complete plant kingdom within its borders, namely the fynbos biome of the Western Cape.

We in South Africa are fortunate to have a particularly rich variety of plants and animals in our own country. Are we aware of this wealth?


People are at the helm, but often fail to do the right thing

Activity: to take a stand on the maintenance of biodiversity in nature

Discuss the following question during the lesson:

  • Are people part of a natural ecosystem, or are they unwanted guests who interfere and disrupt the balance?

Report the outcomes of the discussion in your own words (the dominant opinion within the group).

[ LO 3.2]

People are often accused of tapping nature’s resources for their own selfish needs.

If today were a typical day on planet Earth, 336 km² of tropical forest will have been destroyed by the end of the day to provide wood and by making way for roads, farms and plantations. A total of 112 km² will have changed into desert because of overgrazing or poor farming practices.

One and a half million metric tons of dangerous waste will have been dumped in the environment. Various estimates suggest that 50 to 100 plant and animal species will shortly become extinct.

By the end of the day, the world will be a little warmer, the rain will be a little more acidic and the earth’s web of life will be slightly more torn and tattered. (Chiras, 1993)

Scientists warn us against humankind’s destructive trends. the idea of sustainability suggests that it is possible for nature and human beings to exist in a win-win relationship. at the recent world conference in johannesburg, it became clear that many people believe that we can ensure a positive future for the whole world with the right management systems and the right inclination.

Activity: to reflect on the sustainability of the earth’s resources

1. List all the mistakes that people are making, with regard to the environment.

2. What do you understand as the meaning of SUSTAINABILITY?

3. Name THREE natural resources that are over-utilised.

4. Give the meaning of Mahatma Gandhi’s words (quoted below) in you own words:

"The world contains enough for everyone's need, but not for everyone's greed."

5. Why should we give serious reconsideration to our use of the environment?

Important terms are:

  • HABITAT : specific place where an organism lives
  • BIODIVERSITY : the variety of life on earth
  • RESOURCES : everything that we use for our survival

Activity: to make a prediction about the earth’s future

The earth is like a spacecraft – all the provisions have been supplied and the journey has to be continued self-supportively!

Create an A4 poster to represent your view of the earth as a spacecraft.


Could you answer the questions and provide a good representation of the earth for your poster?

[ LO 3.2]


Learning outcomes 3: Science, society and the environment

The learner will be able to demonstrate an understanding of the interrelationships between science and technology, society and the environment.

This is evident when the learner

  • understands sustainable use of the earth’s resources.



  • Instruct the class to do silent reading.


  • The earth is like a spacecraft – all its supplies have been provided and it has to set out on its voyage – completely self-supportively!!
  • Create an A4 poster to depict your image of the earth as viewed as a spacecraft in the present time.

Questions & Answers

what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Natural sciences grade 8. OpenStax CNX. Sep 12, 2009 Download for free at http://cnx.org/content/col11050/1.1
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