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Number of germinating seeds

2 0
3 4
4 10
5 15
6 28
7 35

3.1.Name the independent variable in this investigation.(1)

3.2.Name the dependent variable in this investigation.(1)

3.3.Name TWO ways in which the investigation could be improved to obtain accurate and valid results.(2)

3.4.Describe the relationship between pH and the number of germinating seeds. (2)

3.5.Suggest THREE strategies that the government can use to help reduce the formation of acid rain. (3)


The graph below shows the effect of biocontrol on an invasive alien plant population.

Graph showing the effect of biocontrol on an invasive alien plant population.

4.1.Explain what is meant by the term ‘biocontrol’.(1)

4.2.Give two reasons that you can see from the graph to support the fact that biocontrol has been successful in controlling the alien plant population. (2)

4.3.Why is host specificity so important when introducing a biocontrol agent?(2)

Read the following text and answer the questions that follow:



In the year 2000, indoor air pollution from solid fuel use was responsible for more than 1,6 million annual deaths. Smoke and gases that come from the burningof fossil fuels, such as coal, charcoal and wood, to heat homes and to cook contributes to indoor pollution.

Dependence on burning fossil fuels to meet basic energy needs is one of the underlying causes of asthma, bronchitis, pneumnia and other respiratoryillnesses among children.

Adapted from: http://www.who.int/indoorair/health_impacts/burden_global/enprint.html

5.1 Name THREE illnesses that are thought to be made worse by exposure to indoor pollution.(3)

5.2 Why do you think indoor pollution causes so many medical problems?(2)

Suggest TWO ways in which communities can try to decrease the negative effects of indoor pollution.(2)

Studies show that the average South African has a “carbon footprint” that is higher than the world average because most of our electricity isgenerated from burning coal.

5.3 State THREE ways to solve this problem.(3)

Question 6

(NSC Additional Exemplar 2008 Life Science Paper 2 Question 1)

Study the table below showing the amount of medical waste produced by three provinces over a number of years


Amount of medical waste (tones)






Province A 357 398 410 426 450
Province B 283 290 300 312 330
Province C 230 240 245 270 290

6.1Which province has shown the most rapid increase in the amount of medical waste produced?(1)

6.2What was the percentage increase of medical waste produced by the province named in QUESTION 2.1 over the period 1995 to 2003? Show ALL workings. (3)

6.3Give TWO negative effects of dumping medical waste.(2)

Question 7

The graph below shows the effect of different amounts of sewage discharged into a river, on the amount of dissolved oxygen in the water. Study the graph andanswer the questions that follow.

7.1.Why does the sewage discharge cause oxygen levels to decrease?(2)

7.2.Why does the minimum amount of oxygen occur some distance downstream of the point of sewage discharge?(2)

Questions & Answers

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
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.
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
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
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Comment on the ozone depletion over the period of 1982 to 1996
Mpho Reply

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Source:  OpenStax, Siyavula: life sciences grade 10. OpenStax CNX. Apr 11, 2012 Download for free at http://cnx.org/content/col11410/1.3
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