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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

how do they get the third part x = (32)5/4
kinnecy Reply
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
okay, so you have 6 raised to the power of 2. what is that part of your answer
I don't understand what the A with approx sign and the boxed x mean
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
I'm not sure why it wrote it the other way
I got X =-6
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
oops. ignore that.
so you not have an equal sign anywhere in the original equation?
Commplementary angles
Idrissa Reply
im all ears I need to learn
right! what he said ⤴⤴⤴
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
is it 3×y ?
Joan Reply
J, combine like terms 7x-4y
Bridget Reply
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
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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