<< Chapter < Page Chapter >> Page >

Figure 1 above represents a very “young” population. The vast majority are under 20 years of age, which also means that the population growth will be very high.

2. The population distribution across the globe

Activity 1:

To answer questions about the distribution of the world population

[lo 1.5]

  • The world population is not distributed evenly. Why not ? Study the world map [fig.2, population distribution] and other maps in your atlas, and answer the questions that follow

a) Why is the population so sparse at a , b and c ?

b) Why would the population at d and e be equally sparse?

c) Does the Amazon River in Brazil have anything to do with the population density in that country? (Explain)

d) Explain the reason for the densely populated area in the north-eastern corner of Africa.

e) Would you say that the whole of Australia has become urbanised?

The world population is not distributed evenly across the globe – in some parts the population is very high, while in others it is rather low. The reasons for this may vary from region to region, and from country to country. In the same way the population structures (with regard to e.g. age distribution) might also vary – one area would have an “old” population, while another would be regarded as “young”. Also, these characteristics of the population do not remain static – some regions could experience depopulation, while others might experience rapid urbanisation. In the same way a population could within 50 years possibly change from “young” to “old”. Could you think of any nearby town or village having either a “young” or “old” population? Why would that be? Has it already changed, or is it likely to change in any way, and why?

3. Population structures

This young population as depicted by means of the population pyramid in figure 1 on p. 5 was that of England and Wales in 1881. Fifty years later the picture looked quite different, and after a further fifty years it showed even more change. This type of change is called demographic development.

Important features of a population represented by means of a typical pyramid (having a broad basis), are (a) a high birth rate, (b) a high death rate, (c) short life expectancy.

The increase in the population of any group (a country or community) is calculated by means of the following formula:

Pg = b –d (+ or – net migration)

Pg is the P opulation g rowth

B is the B irth rate

M is the D eath rate

immigrants are added

emigrants are deducted

Activity 2:

To make inferences about population increase

[lo 3.2]

a) Is it possible that the Pg does not show an increase , but a decrease ? Motivate your answer.

3.1 Is the new baby going to be a male or female ( a boy or a girl)?

We take it for granted that an equal number of boys and girls are born in a big community or country . This means that in big, co-educational schools, one would usually find a more or less equal number of girls and boys. A drawing of the school’s “population pyramid” (watch out: it will not be shaped like a pyramid, but could you explain why?) would therefore be symmetrical .

Questions & Answers

what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
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
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
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.
Bharti
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
Daniel
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
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
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
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
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.
Tarell
what is the actual application of fullerenes nowadays?
Damian
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.
Tarell
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.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
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.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Geography grade 7. OpenStax CNX. Sep 09, 2009 Download for free at http://cnx.org/content/col11021/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Geography grade 7' conversation and receive update notifications?

Ask