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Natural sciences

Ecosystems and the environmental balance

Educator section


5. Antelopes: moderate grassland; subtropical grass and thorny bushes; bushveld

proteas: fynbos

ferns and mosses: moderate forests

grasshoppers: semi-desert; moderate grassland; bushveld

karoo bushes: semi-desert; dry semi-desert

lions: bushveld; sub-tropical lowveld

succulents: desert; semi-desert

Leaner section


Activity: to understand the concepts “biomes” and “symbioses” [lo 1.1]


Within the biosphere the climate differs from place to place, and there are many natural regions, each with its own characteristic plant and animal species, as illustrated in the map above. The natural regions are called biomes. (You will learn more about it later).

A continuous interaction takes place between the living and non-living organisms in each biome.

In which region(s) would one find plenty of?


proteas _______________________________________________________________

ferns and mosses_______________________________________________________

locusts _______________________________________________________________

karoo bushes__________________________________________________________



What an animal eats, determines where it lives! Antelope that feed on the leaves and young offshoots of trees, will not be found in places where the vegetation is mainly bushes and shrubs. One will not find leopards and lions where there are no antelope.

(a) What an animal eats, determines where it lives

Some birds cannot stay in one habitat all year round, because trees shed their leaves because of weather patterns. One such species is the swallow. To overcome this problem, swallows therefore migrate to countries where it is summer and return again after winter.

Assignment 13

Write a short paragraph on the migration of the swallow. Indicate whether it is an annual occurrence, and also how the migration takes place and what problems the birds experience during their migration.













The diet of an Eskimo living near the North Pole mainly consists of seal-meat, fish and birds. All these sources are dependent on small plants which grow in the sea. But how is this possible?

Seals and birds feed on fish. The fish eat smaller fish. Little fish feed on shrimp, whilst the shrimp feed on microscopic plants called diatoms, which live on the surface of the sea. These plants produce their own food through the process of photosynthesis.

Complete the long chain of who eats whom:

Ecologists call the transfer of food energy from a source to numerous organisms feeding successively on each other, a food chain.

(b) Symbiosis

The symbiosis relates to the cohabiting of plants and animals to the advantage of one another. The story of mangroves and crabs is probably one of the nicest stories of symbiosis between plants and animals. Mangroves especially grow in the salty water where rivers discharge into the ocean. The soil there is very poor, muddy, without air and salty. Fortunately there are also crabs that live in the muddy estuaries. One such crab, the mangrove crab, survives on dead leaves which they store in tunnels. These crabs make holes and tunnels in the mud and manufacture humus of good quality from the decomposed leaves. There is, however, one problem that they had to overcome, and that is the fact that the trees only shed their leaves in autumn. During the other seasons there weren’t leaves for the crabs to use. The mangroves therefore changed their leaf shedding habits. They don’t shed all their leaves at the same time, but throughout the year. In this way they live together to the advantage of one another.

Assignment 14

Do research on any other interesting form of symbiosis between animal and plant. Write a short report (one folio) or make a sketch that depicts symbiosis.

CRITERIA 1 2 3 4 5
Indication of two organisms ___ ___ ___ ___ ___
Reasons for symbiosis ___ ___ ___ ___ ___
Language / captions with sketch ___ ___ ___ ___ ___
Neatness and layout ___ ___ ___ ___ ___
Element of interest ___ ___ ___ ___ ___

Consider another food chain more familiar to us.

In a field green plants are eaten by meadow mice, which in turn fall prey to hawks.

The hawk is a secondary consumer.
The mouse is a primary consumer, because it is the first to eat the plants.
The green plants are the producers.

The concept of producer and consumer is very helpful in nature because it reminds us that food is not manufactured in canneries or frozen-food factories out there.


Learning Outcome 1: The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

Assessment Standard 1.1: We know this when the learner plans investigations.

Questions & Answers

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
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
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?
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.
what is biological synthesis of nanoparticles
Sanket 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
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 6. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11079/1.1
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