Sec 2 CT1.2010 Answer

Here is the marking scheme for your Common Test (Term 1, 2009)
Please understand that this is only a guideline. I must read your whole answer in context in order to award the correct marks.

Normal (Academic)
Qn 1(a)(i)

• Country A = Birth Rate - Death Rate = 11/1000
• Country B = Birth Rate - Death Rate = 5/1000

Qn 1(a)(ii)
Country C
This country has the highest rate of natural increase. This means, of the four countries, it has the largest number of people added to the population each year.

Qn 1(b)
Medical care refers to the availability of hospitals, clinics and doctors.
Health care refers to immunization, nutritional knowledge and measures in improving quality of life.
More babies will be able to survive their first year if there are better medical care and health care.
With lower infant mortality rate, death rate will drop.
When elderly receive better medical care, their life expectancy will also increase/live longer.
As life expectancy falls, death rate will also decrease.
With a cleaner/more hygienic environment, people will be less prone to falling ill and contracting diseases.
Death rate will usually decrease drastically when there is a good supply of clean water.

Qn 1(c)
Educate people on the importance of family planning and methods of controlling family size.
Penalise couples with more children.
Reward couples who keep their families small.

Qn 2(a)(i)
Population density gives us an idea of the number of people living in a particular area.
It is usually expressed in terms of the number of people per square kilometer of the land.

Qn 2(a)(ii)
Year 1910, PD = 40244/44 = 91/km2 (est.)
Year 1960, PD = 13357/ 44 = 303/km2 (est.)
Year 2000, PD = 45386/ 44 = 1032/km2 (est.)

Qn 2(a)(iii)
Population density will increase as population increase, when the land area remains constant.

Qn 2(b)

• Demand for food and water increases as population rises.
• Many less developed countries have difficulties supplying enough food and water to meet this demand.
• This is worsened when population is increasing very rapidly.

• This rapid increase also results in competition for housing.
• Without sufficient housing for its growing population, it becomes common for people to live in temporary shelters such as cardboard or wooden planks.
• Demand of resources is not the only problem caused. The amount of waste produced by an increasing population is also a problem.

• Increasing population would also produce greater amount of waste products.
• Very often less developed countries are not able to provide enough service to clear these waste.
• This problem will eventually lead to water and land pollution.

Express
Qn 1(a)(i)
Population Density = Population/Land Area (km2)
Year 1910, PD = 40244/44 = 91/km2 (est.)
Year 1960, PD = 13357/ 44 = 303/km2 (est.)
Year 2000, PD = 45386/ 44 = 1032/km2 (est.)

Qn 1(a)(ii)
Population density will increase as the population increase, when the land area remains constant.

Qn 1(b)(i)

• People in the less developed countries generally receives less education and know little about family planning methods.
• This lack of knowledge hinders them from limiting the number of children born to the family.
• They may also be deeply rooted in traditional beliefs which encourage them to have more children.
• This is especially true for asian countries where sons are preferred, and are required to perform religious rituals for the parents.
• Women in the less developed countries tend to marry at a younger age.
• This in turn increases their childbearing years and the number of children born.
• Many less developed countries are still depending on agriculture. Farm work requires much labour.
• When families have more children, more will be able to work on the farms.
• In addition, when daughters marry, they will leave the family and therefore reducing the manpower on the farm. But sons will remain with the family and continue to work on the farm until the parents are old.

Qn 1(b)(ii)

• Demand for food and water increases as population rise.
• Many less developed countries have difficult supplying enough food and water to meet this demand.
• This is worsened when population is increasing very rapidly.
• This rapid increase also results in competition for housing.
• Without sufficient housing for its growing population, it becomes common for people to live in temporary shelters such as cardboard or wooden planks.
• Demand of resources is not the only problem caused. The amount of waste produced by an increasing population is also a problem.
• Increasing population would also produce greater amount of waste products.
• Very often less developed countries are not able to provide enough service to clear these waste.
• This problem will eventually lead to water and land pollution.

[Award max. 2 marks for explanation of each problem. Only 2 problems required.]

Qn 2(a)(i)

• Country A = Birth Rate - Death Rate = 11/1000
• Country B = Birth Rate - Death Rate = 5/1000

Qn 2(a)(ii)

• Country B
• This country has the lowest rate of natural increase. This means, of the four countries, it has the least number of people added to the population each year.

Qn 2(b)(i)

• Bee-hived population pyramid
• The number of children and youth is decreasing
• many people can expect to live up to 80% or longer
• Proportion of youths and children is not very high
• America and Singapore
  

Qn 2(b)(ii)

• With a lower rate of population growth, percentage of elderly will eventually increase compared to young people in the country.
• With more elderly people and fewer youths joining the workforce, the burden on the working population will increase.
• Taxes collected by the working population fund public projects (such as building of community hospitals, swimming pools and libraries)
• As the population shrink, fewer people will join the workforce. This means each working population growth, there will be fewer people to lead and serve the country.
• This is especially important for nations,like Singapore, with small population.

Common Test Reflection

Generally, I sense that most students have studied or at least understood the concepts and ideas in the 2 topics. I think the challenge now is learning how to apply your knowledge, understand the questions and reading the data.

For those who really studied and failed to meet your personal target/expectation, don't be discouraged. Remember we're working towards the final grade at the end of the year. Continue to work hard for Term 2 and 3, and make sure you understand what went wrong this time. This is very very important.
And then there are those who did not work hard enough (studying the night before is not working hard!), I don't think I need to say very much to you. I hope your conscience has been speaking.
And also... those who claimed they did not study and still did well. I suggest you apply and sit for this year's O level exams then! >:-(

Top Geography Students (female/male):
2G - Nur Liyana (23), Ezekiel Liew (24)
2F - Tessa Soh Hui Shan (27), Ong Jia Jun (31)
2E - Yee Isabelle (34), Issac Chua (28)
2D - Chioh Wen Jing Florence (29), Liang Zhisen (28), Tan Yong Xun (28)
2C - Kong Wai Shuen Tricia (33), Lim Yee Siang Ashley (33), Said Effendy B Said Iziddin (33)
2B - Cheryl Yip Yi Xiu (35), Kuick Yi Shao Glen (34)
2A - Ang Yu Ting (30), Chan Yong Ming (27), Kiew Rayren (27)

Sec 2 Normal (A) CT1.2009 Answer

Here is the marking scheme for your Common Test (Term 1, 2009)Please understand that this is only a guideline. I must read your whole answer in context in order to award the correct marks.

Question 1ai)
- Similar pattern for all 3 gases
- Increase slower/steadily before 1900
- Begin accelerating after 1900
- Sharp increase around year 1950/ very steep curve

Any 3 clear descriptions of the trend/pattern observed in the graphs.
1 mark for only mere description of any graph without stating any trend or pattern.


Question 1aii)
- Increase population (esp. sharp increase around 1950) leads to increase demand for food and land
- More forests are destroyed for food/agricultural and residential purposes
- When more forests are destroyed, CO2 in the atmosphere will increase. Moreover, some forests are destroyed through burning, which will release more CO2.
- Increased wet rice farms and cattle ranches caused by demand from a larger population increases the release of methane
- More fertilisers are used on farms to increase food production. This account for the increase in nitrous oxide in the atmosphere.

5 points @ 1 mark each


Question 1bi)
- Carbon Dioxide [1]
- CO2 remains in the atmosphere a lot longer than most of the other gases
- CO2 is released into the atmosphere on a daily basis e.g. burning of fossil fuel
- Industrialisation and number of motor vehicle on the road is still increasing as more countries become develop
- Deforestation removes trees, which should control the amount of CO2
- Deforestation which involves burning of trees will further increase amount of CO2

1 mark allocated to name of gas
Max 5 points @ 1 mark each; for explanation


Question 1bii)
- Increasing global temperature leading to the melting of glaciers, ice in north and south pole
- Habitat of polar bears (Arctic circle) is being destroyed as the ice melts
- Without suitable habitat for food and reproduction, the polar bear will face extinction
- Global warming will cause more extreme weather condition (e.g. hotter summers, flooding)
- Farmers are unable to cultivate crop during the expected seasons, and harvest is destroyed by the extreme weather
- This harvest usually provide food for the Cambodians for the rest of the year
- This results in food shortage for the Cambodians in year 2002

2 marks for each phenomenon, or max.
Students expected to explain all 3 phenomenon. Total of 6m.


Question 2ai)
- Fertiliser runoff/ pesticide dusting - when farmers use fertilisers/ pesticide excessively, the rain will wash the excess into the river and pollute its water
- Oil Spill - tanker accidents will pollute the sea with oil that its carrying; the action of the wind and waves will spread the oil over a large area of the sea
- Urban waste/ industrial waste/ septic tank - sewage from the urban city/ industries/ household might be discharged/disposed into the river before it has been treated at the sewage treatment plant
- Leakage from the septic tank might also pollute the river water when it's carried by the underground water
- Non-biodegradable substances cannot be broken down even if it goes through sewage treatment. They are then discharged into the sea, polluting the water

2 marks for each way explained. No marks for mere listing.
2 marks X 3 ways (Total 6 marks)


Question 2aii)
- during an oil spill, a layer of oil will spread over the sea; sea birds and mammals who come into contact with the polluted water will dirty their feathers and fur
- the oil will remove air trapped by the feathers and fur, causing these creatures to either freeze to death or drown
- sea creatures who consume the polluted water will also be poisoned
- sunlight will also be blocked by the layer of oil, thus affecting the growth of aquatic plants and planktons beneath
- when the oil is washed ashore, the beaches will also be polluted; this in turn also affect any plants or creatures which are found on the polluted beaches

5 points @ 1 mark each


Question 2bi)
- dust and smoke particles can cause irritations in people's throat and eyes
- in more serious cases, they can also suffer from respiratory problems (such as asthma and bronchitis)
- toxic gases (sulphur dioxide and nitrogen oxides) which pollutes the atmosphere also attack the respiratory system, giving rise to lung and heart diseases
- when exposed to air pollution over a long period of time, the lifespan of these victims can also be shortened
- when workers fall ill and go on medical leave, the workforce will be affected and production drops

4 points at 1 mark each
1 mark for just lifting the answer from the passage

Question 2bii)
- Power stations and manufacturing plants are usually found in the cities. These are major sources of pollution
- As fossil fuel is burnt to generate power and in the process of manufacturing, soot and sulphur dioxide are produced
- The number of motor vehicles on the city road is also much higher than the country side.
- Vehicle emission contains harmful gases such as carbon monoxide and nitrogen oxides into the atmosphere
- Construction of buildings also takes place rapidly in the city area. This activity create huge amount of dust particles and smoke, thus adding to the problem of air pollution

5 points @ 1 mark each

Sec 2 Express CT1.2009 Answer

Here is the marking scheme for your Common Test (Term 1, 2009)
Please understand that this is only a guideline. I must read your whole answer in context in order to award the correct marks.

Sec 2 Express

Question 1ai)
- Similar pattern for all 3 gases
- Increase slower/steadily before 1900
- Begin accelerating after 1900
- Sharp increase around year 1950/ very steep curve
Any 3 clear descriptions of the trend/pattern observed in the graphs.No mark for only mere description of any graph without stating any trend or pattern.

Question 1aii)
- Increase population (esp. sharp increase around 1950) leads to increase demand for food and land
- More forests are destroyed for food/agricultural and residential purposes
- When more forests are destroyed, CO2 in the atmosphere will increase. Moreover, some forests are destroyed through burning, which will release more CO2.
- Increased wet rice farms and cattle ranches caused by demand from a larger population increases the release of methane
- More fertilisers are used on farms to increase food production. This account for the increase in nitrous oxide in the atmosphere.
5 points @ 1 mark each

Question 1b)
- Carbon Dioxide
- CO2 remains in the atmosphere a lot longer than most of the other gases
- CO2 is released into the atmosphere on a daily basis e.g. burning of fossil fuel
- Industrialisation and number of motor vehicle on the road is still increasing as more countries become develop
- Deforestation removes trees, which should control the amount of CO2
- Deforestation which involves burning of trees will further increase amount of CO2
6 points @ 1 mark each

Question 1c)
- Increasing global temperature leading to the melting of glaciers, ice in north and south pole
- Habitat of polar bears (Arctic circle) is being destroyed as the ice melts
- Without suitable habitat for food and reproduction, the polar bear will face extinction
- Global warming will cause more extreme weather condition (e.g. hotter summers, flooding)
- Farmers are unable to cultivate crop during the expected seasons, and harvest is destroyed by the extreme weather
- This harvest usually provide food for the Cambodians for the rest of the year
- This results in food shortage for the Cambodians in year 2002
2 marks for each phenomenon.
Students are expected to explain all 3 phenomenon. Total = 6m

Question 2ai)
- increasing car ownership will lead to more vehicles on the road
- this leads to an increase in the burning of fossil fuel
- when this happens, vehicles emit large amount of dust and soot, and poisonous gases, such as carbon monoxide and nitrogen oxides into the atmosphere
3 points @ 1 mark each

Question 2aii)
- As Beijing becomes more developed, more power is generated in the power station.
- There will also be more manufacturing plants in the city
- The burning of fossil fuel from these sources will release greater amount of soot, and poisonous gas such as sulphur dioxide into the atmosphere
- In addition, more buildings will be built to accommodate the increasing population and businesses
- The clearing of land, construction of buildings and even transportation of building materials will increase the amount of dust and smoke particles in the atmosphere.
- These contribute to the air pollution in Beijing
Max 1 mark for mere listing of factors without any brief explanation.
1 mark for activity + 1 mark for description/brief explanation; total 2 activities

Question 2aiii)
- When there is severe air pollution, people in Beijing will experience health problems such as asthma and bronchitis
- In severe cases, the toxic gases will attack their lungs and cause lung diseases. In some cases, this will eventually lead to death
- Air pollution will affect the workforce when more people have to take medical leave due to poor health
- Air pollution will also affect visibility and therefore affect transportation
- There will be more accidents on the road, hindering the transportation of goods and people
- Planes at airport might not able to take off and this will also affect the tourism and import/export industries.

6 points @ 1 mark each
Max 3 marks for either economic effects or social effects
Max 1 mark for mere listing of effects


Question 2bi)
- The waste of the infected person can be deposited into the septic tank or at a river.
- If there are cracks in the septic tank, the bacteria will travel/spread underground towards the well. Bacteria from the river will also flow underground towards the well
- When the bacteria enter the well, the well water will become polluted with the bacteria
3 points @ 1 mark each

Question 2bii)
- People who uses/consume the well water and river directly will fall sick
- Children who bathe and play at the river will also contract the illness
- Fishes in the river might become infected with the bacteria
- If these fishes are caught as food supply for the community, people who consume them might also fall ill

4 points @ 1 mark each
Proper explanation expected; e.g. of unacceptable answer: "People fall sick."

Common Test (Term 1) 2009

When:
27th Feb 2008 (Friday)
Period 2

What:
Focus for this test is on Air, Water & Land Pollution (textbook pg 142 - 150) and Global Warming: Causes and Consequences (textbook pg 168 - 173)

Format:
2 Structured-essay questions worth 20 marks each. Each question will be divided into parts, e.g. Qn 1ai), Qn 1aii)
Total marks for the test will be 40.
Time allocated: 1 hour

Note:
Study the basic information/knowledge from your textbook to be familiar with the ideas, terms and chemical names, etc.
Read through (seriously!) the questions and answers in your workbook exercises AND supplementary worksheets given in class.
Make sure you are able to write out your explanation independently as you revise.