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Natural sciences

Grade 8


Module 38

The role of water in nature and its role as a resource


To be able to explain the value of water and the water cycle

[lo 1.3; lo 2.3; lo 2.4]

Our planet looks blue from outer space because of the water on its surface.

Water is indispensable for life on our planet. Without water ecological survival would not be possible.

Our planet is equipped with a certain quota of water – just as a spaceship would be. The water is not replenished from outer space, but has to CIRCULATE. Thus the WATER CYCLE is an extremely important aspect of nature. It is also most effective if humans do not disturb it.

The Water Cycle

Draw a representation of the water cycle as you understand it. Use explanatory captions. Use the table on the following page as a guideline.


Were you able to represent basic components and definitions GRAPHICALLY?

[LO 2.3]

El Niño, droughts and floods

  • On comparing the rainfall statistics of South Africa to those of other countries, one sees very clearly that South Africa is an arid country.
  • Only some of the larger rivers flow permanently.
  • Furthermore, our climate and rainfall patterns are determined by phenomena such as El Niño. This is a world-wide weather phenomenon and precautions must be taken to cope with it.

1. Find out more about El Ni ñ o and report back to the class. Make a brief summary of your notes.

2. Find articles on droughts and floods in South Africa and bring them to class. Swap information and articles. Make notes on the subject.

[LO 1.3]

Use graph paper and draw two column graphs in different colours to represent the rainfall patterns in the two provinces.


To look into the value of water and its use in and around the house

[lo 2.3; lo 3.2]

Water consumption at home

Ask your parents or guardians for their municipal accounts.

  • Write down your domestic water consumption for six months (three summer months and three winter months).

Summer months: 1. ......................... 2. ......................... 3. .........................

Winter months : 1. ......................... 2. ......................... 3. .........................

  • Do you think that your water consumption is excessive?

Saving water at home

How can your family contribute towards saving water? What can YOU do?

  • Make a list of your best suggestions:


Were you able to make feasible suggestions concerning WATER CONSERVATION?

[LO 3.2]


To examine the adaptations of plants and animals with regard to water shortage

[lo 1.3; lo 2.3]


  • In a previous module reference was made to plants that can be classified into three groups, according to their water requirements.

Name the three groups and give an example of each.

  • Plants have numerous adaptations and survival strategies, especially with regard to water shortages.
  • Xerophyte leaves have been modified to thorns in cases such as the cactus plant groups. Other plants, such as the aloe, about which you had to do a project, store a great deal of water in their fleshy leaves through protein bonding.
  • The leaves of mainly xerophytes are thick and fleshy and unpleasant or bitter to the taste to deter animals from eating them. In this way they prevent the plant from being robbed of its valuable moisture.
  • The leaves of plants that have been adapted to arid conditions for survival are often sessile (no leafstalk) and they are arranged in such a way that any water that collects on the leaf (e.g. dew) will run down the stem so that the roots can absorb it.
  • The leaves of some other plants roll up when it is very dry, so that evaporation is limited. For example, see what the leaves of the maize plant look like when it hasn’t rained for a long time.

Questions & Answers

How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
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
How can I make nanorobot?
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
how can I make nanorobot?
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
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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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