1. the Scientists Carried out a Controlled Experiment That Supported the Hypothesis

1. The scientists carried out a controlled experiment that supported the hypothesis:

Cane toads are attracted to UV light.

Describe a method for a controlled experiment to test this hypothesis......

Extended response question3

In the future, the quality of our lives and the environment will depend on how society deals with problems such as climate change, natural events and how we obtain and use energy.

Evaluate an impact of an environmental problem. In your answer, show how science can help reduce the impact on society and the environment.

Environmental problem: ......

2. You have been asked to prepare a talk for Year 9 students on the features and functions of DNA.

Outline the information you would present in your talk. In your outline, identify ONE diagram you would include and give a reason for your choice. (It is NOT necessary to draw the diagram.)

......

3. Read the information below about iodine.

Iodine is an important element both for healthy humans and the chemical industry. The thyroid gland in our necks uses iodine to make a hormone called thyroxine. The blood carries thyroxine to all parts of our bodies.

Thyroxine affects the way our cells work. Adults can become unwell through a lack of iodine in the diet. Iodine can come from the soil but richer sources of iodine are seafoods and dairy products. Also some brands of table salt have iodine added to them.

The main source of iodine in the chemical industry is sea water. Iodine can be manufactured by reacting chlorine gas with sodium iodide (the salt) from sea water.

(a) State the role of hormones in the human body......

(b) Write a word equation for the reaction that produces iodine......

(c) Iodine deficiency is an example of a non-infectious disease. Why is iodine deficiency classified as non-infectious? ......

(d) – 30 – Scientists have identified a lack of iodine in the diet of many Australians.

(i) Propose a possible cause for this lack of iodine in the diet......

(ii) Describe how the mass media could assist in solving this problem......

4. (a) A scientist uses detectors to determine if an element is radioactive.

If an element is radioactive, what would be released from its nucleus?

......

(b) Radioactive elements contain atoms whose nuclei can change.

Radioactive elements can be used in the field of nuclear medicine. Describe ONE benefit and ONE problem associated with the use of nuclear energy in medicine.

Benefit: ......

......

Problem: ......

6.The Tasmanian Devil is a small mammal found in scrubland in Tasmania. Scientists have recently become concerned because the number of Tasmanian Devils caught or seen in the wild has changed.

In 1975, the number of Tasmanian Devils seen in a 25 square kilometre area around the city of Hobart was 400. In the same area in 2004, only 100 animals were seen. As a result, scientists have kept their exact location secret and turned the area into a nature reserve.

(a) Suggest ONE reason why scientists have turned the area where Tasmanian Devils were seen into a nature reserve.

(b) Identify ONE other way that scientists could conserve Tasmanian Devils......

......

(d) Give ONE reason why society should support scientific research about Tasmanian Devil numbers.

......

7. (a) Name a type of electromagnetic radiation that is used in communication.

......

(b) Identify ONE advantage and ONE disadvantage of using this type of electromagnetic radiation for communication.

Advantage ......

Disadvantage

......

8. (a) Name an example of a technology or invention developed by scientists......

(b) Explain how an advance in technology has increased scientific knowledge......

9. Melissa suggested that coffee in plastic cups stays hot longer than thick

tomato soup in plastic cups.

Plan a safe experiment to test this idea.

......

10. Construct a table to show which of the following reproductive organs are

female and which are male:

ovary, urethra, Fallopian tube, cervix, testis, prostate gland, vagina.

11. The diagram shows some newspaper headlines related to biotechnology.

GM foods

hit the markets Genetic engineering produces

human proteins

Transgenic species – new

DNA fingerprinting

Artificial selection

Cloning reaches

new heights

Select ONE of these biotechnologies, or ONE you have studied in class.

Discuss TWO impacts of its use on society.

Type of biotechnology: ......

......

12. A new power plant for generating electricity is to be built in a bushland

area.

Identify TWO potential impacts on the environment of building this new

power plant.

......

(b) In Australia, most electricity is generated either by burning coal or by

water flowing through a hydro-electric power plant.

Reasons that support the method of electricity generation you

believe has LEAST impact on the environment.

......

2004 SCT • SCIENCE • SECTION 2 • PART C

13. Construct a table to indicate which of the following factors are biotic and

which are abiotic:

Bacteria, oxygen, temperature, humans, soil acidity, water, insects.

14. The people of Xinbu, a village in China, are now generating

electricity and producing their own fertilisers using biogas

digesters.

Abiogas digester is a place where plant and animal wastes decay

to produce heat and methane gas. The wastes used include

human and animal wastes, sugar, grass and bananas. The

methane gas produced is used for cooking, lighting and

generating electricity. The decayed wastes are then recycled as

fertilisers for their crops.

Assess TWO impacts on the environment of using biogas digesters.

......

15. Design an experimental investigation to test the following idea:

When you drop a heavy ball it will take the same amount of time to reach the

ground as a lighter ball.

......

2003 SCT • SCIENCE • SECTION 2 • PART C

16. A nuclear reactor is nearing the end of its useful life. Many scientists and

doctors want a new reactor built to serve the needs of the community.

Some local residents and anti-nuclear groups want the nuclear facility

closed. They are concerned about a fault line in the area that could move

during an earthquake. They are also worried about wastes from the reactor

being washed into local creeks and waterways.

a. Explain why people would worry if wastes from the reactor washed into

waterways.

......

( b) Other than wastes, state ONE additional problem associated with nuclear

reactors.

......

justify the building of a new reactor.

......

17. Outline the theory of evolution by natural selection.

......

18. Scientific investigations can be carried out individually or in groups (teams).

Describe TWO advantages of each approach.

Individual approach

(i) ......

......

(ii) ......

......

Group approach

(i) ......

......

(ii) ......

......

19. A student wants to test the idea that strawberry plants grow better in soil at

10°C than in soil at 20°C.

Design an investigation to test this idea.

......

20. Colonies of fire ants have been discovered in towns in northern New South

Wales. Fire ants can be poisoned using a pesticide.

Some scientists suggested spraying pesticide on infested areas. Environmental

scientists are worried about the effects the pesticide might have on the

environment.

(a) Outline TWO concerns the environmental scientists might have.

......

(b) Other scientists have suggested the introduction of a predator to kill the

fire ants instead of spraying pesticide. Assess ONE possible impact of

this strategy.

......

21. (i) Draw a circuit diagram to show a switch, a battery and two

globes with the globes connected in parallel.

(ii) The light globes on Christmas tree lights are connected in parallel.

Why is it an advantage to connect these lights in parallel rather

than in series?

......

22. Some herbal remedies are used in ways similar to conventional medicines

prescribed by doctors.

Design an investigation you could undertake to compare the effectiveness of

ONE herbal remedy and ONE conventional medicine that are both used to

relieve swelling caused by insect bites.

......

23. Select a biotechnology that you have studied, and discuss the impacts on society of its

development and use.

Biotechnology ......

......

24. In many scientific studies, several variables can affect the results.

You want to investigate two related areas:

1 Male rats eat more than female rats do.

2 Large rats, regardless of their sex, eat more than smaller rats do.

(a) Design an experiment to test ONE of these two ideas.

......

(b). Imagine you have carried out this experiment. Your results supported the idea

you tested.

Design and complete a table to show the results you obtained.