1.
The use of plastic materials adds to the pollution of the environment. Which of the following statements explain it?A: They take a very long time to decompose.B: They are produced from natural resources.C: They are waterproof.D: They produce harmful gases when burnt.
Correct Answer
B. A and D
Explanation
Most plastics are made from chemicals obtained from petroleum. Unlike biodegradable materials, non-biodegradable like plastic takes a very long time to decompose and they produce harmful gases when burnt.
2.
Which of the following activities does not have a negative impact on the environment?
Correct Answer
B. Planting trees in a nature reserve
Explanation
Reforestation is the process of planting new trees to an area. It would bring about positive impact to our environment.
3.
What may result when the environment becomes unfavourable to the organisms?A: The organisms may die.B: The organisms may adapt.C: The organisms may move to another place.
Correct Answer
B. A and C
Explanation
When the environment for the organisms becomes unfavourable, they are unlikely to survive. Thus, the organisms may die or they may move to another place.
4.
A large area of forest was destroyed by fire. Which of the following will happen?
Correct Answer
D. Wildlife will be endangered.
Explanation
Burning the forest will destroy the habitats for many wildlife. Thus, many species of the animals become extinct or endangered.
5.
We can reduce land pollution by _________________________________________.A: incinerating rubbishB: reducing deforestationC: using organic pesticides in farmingD: building taller chimneys for factories
Correct Answer
B. A and C only
Explanation
Land pollution is caused by the excessive spraying of pesticides, the indiscriminate dumping of community refuse, and the disposal of rubbish through landfills. Hence, land pollution can be reduced by incinerating rubbish and using organic pesticides in farming.
6.
Which of the following can cause pollution?A: Litter and rubbishB: Harmful chemicalsC: Human wasteD: Biodegradable materials
Correct Answer
A. A, B and C only
Explanation
BioBiodegradable materials are generally organic material such as plant and animal matter and other substances originating from living organisms. Unlike plastic, biodegradeable materaials will decompose over time.
7.
Which of the following are non-biodegradable materials?A: WoodB: PlasticsC:Styrofoam boxD: Prawn shell
Correct Answer
B. B and C only
Explanation
Wood and Prawn shell are from animal or plant origins, therefore, it is considered biodegradeable materials.
8.
Kelly disposed off some clear liquid chemicals into a lake. Which of the following would be observed in the pond community?A: A smell could be detected from the lake.B: The water in the lake was stagnant.C: Dead fishes can be seen floating on the surface of the lake.D: Leaves of plants growing by the lake turned brown.
Correct Answer
D. A, C, and D only
Explanation
Liquid chemcials are toxic to marine life. Therefore, strong smell could be dectected from the lake and fishes would be killed and toxic water from the lake would destroy the plants surrounding the lake.
9.
Insecticides and weedkillers will cause no harm to marine life.
Correct Answer
B. False
Explanation
Insecticides and weedkillers are harmful to marine life.
10.
Irresponsible dumping of rubbish will pollute the environment.
Correct Answer
A. True
Explanation
Irresponsible dumping of rubbish results in land being polluted. Rubbish gives off a bad smell and breed germs. Piles of rubbish also take up space and are unsightly.
11.
Untreated sewage promotes the growth of algae and encourage the growth of marine plants.
Correct Answer
A. True
Explanation
Untreated sewage is toxic to marine life and can also encourage algae growth.
12.
Burning fossil fuels releases harmful gases that will cause acid rain.
Correct Answer
A. True
Explanation
Burning of fossil fuels releases sulphur dioxide and nitrogen dioxide. When sulphur dioxide dissolves in rain water, they form acids, which then fall as acid rain.
13.
Turning up the volume of radios and televisions will not result in pollution.
Correct Answer
B. False
Explanation
Noise pollution is caused by excessively loud noises. Therefore, by turning up the volume of radios and televisions will result in noise pollution.
14.
Species of animals become extinct or endangered due to reforestation.
Correct Answer
B. False
Explanation
Reforestation is the process of planting new trees to an area. By doing so, there will be more habitats for the animals.
15.
In Singapore, rubbish may be sorted into different binds for the purpose of recycling. Which of the following are reasons for recycling rubbish?A: To preserve treesB: to reduce pollutionC: to reduce wastage of materialsD: to get more fertilisers for plants
Correct Answer
D. A, B, C and D
Explanation
The purpose of recycling is to preserve trees, cut down on pollution, reduce wastage of materials and also to get fertilisers for plants.