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pH

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)

QUESTION 4

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:

QUESTION 5:

GLOBAL BURDEN OF DISEASE DUE TO INDOOR AIR POLLUTION

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

Year

Amount of medical waste (tones)

1995

1997

1999

2001

2003

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

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
what is biological synthesis of nanoparticles
Sanket Reply
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
why and for what was five kingdom of classification of organisms introduced
SUBHIKSHA Reply
give the ans as fast as possible
SUBHIKSHA
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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