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QUESTION 20 (13 marks) This question refers to Stimulus 5 6 and 7 in the stimulus book. a) Use Stimulus 5 to contrast the percentage change in the commercial catch of blue swimmer crabs and spanner crabs between 2008 and 2017. [5 marks] b) Use Stimulus 5-7 to draw conclusions about the long-term sustainability of each crab species as commercial native biota. Justify your conclusions using two pieces of evidence for each crab species from any of the stimulus. [6 marks] c) Use Stimulus 6 and 7 to explain two ways to improve the sustainability of either crab species. [2 marks]
QUESTION 1 (9 marks) a) Identify an introduced animal or plant species and explain two reasons why this species is classified as a pest. [3 marks] Introduced species: b) Using a case study about an anthropogenic activity other than introducing a pest species discuss three positive and three negative human influences on the sustainability of an ecosystem on a local scale. [6 marks] Anthropogenic activity:
QUESTION 10 Which anthropogenic factor would most likely affect the sustainable population of native biota? (A) (B) (C) (D) changes to average seasonal rainfall introduction of a new species for biological control increased salinity in rivers through saltwater intrusion planting of grass strips in agricultural systems to reduce erosion
QUESTION 20 (6 marks) Identify two possible environmental risks that could be noted in an environmental impact assessment (EIA) for a new gold mine. Propose a strategy to mitigate each risk and explain the principle behind each Strategy. Risk: Strategy: Principle behind strategy: Risk: Strategy: Principle behind strategy:
QUESTION 13 A farmer has land affected by high salinity. Which solution would have the most impact on reducing it? (A) pump deep groundwater out (B) plant shallow-rooted crops (C) reduce surface drainage (D) initiate deep tillage
QUESTION 19 (5 marks) A study was conducted when a sudden algal bloom was discovered in a waterway that runs adjacent to a dairy paddock. Fertiliser had been applied to the paddock several weeks before. Dissolved oxygen pH and turbidity were measured at various distances from the source of the waterway. — Value So FPF NO W BN Any ww WO Oo CW F—>r'rklkhe SW FF SS Ww je>hh Y Uj Uj 7 U; SSL > e SG 'r>e>e. 0 40 60 8 Distance from water source (m) fo) No om) — S&S jo) Key [Dissolved oxygen (ppm) pH WW! Turbidity (NTU) Draw a conclusion about possible anthropogenic causes of the algal bloom. Show your reasoning referring to each variable measured in the graph.
QUESTION 3 During the last decade a dingo control program was implemented in the Granite Belt region to reduce loss of lambs. This resulted in an increase in the population of wallabies and feral cats and a decrease in the population of rat species. The program also resulted in a loss of native plant species. With this decrease in plant species the population of herbivore species decreased. A decision was made to stop the control program and erect dingo fencing around native parks to allow numbers to recover. Which of the following scenarios presents the most likely consequences of stopping the dingo control program? (A) dingo population increased wallaby population decreased flora unaffected (B) dingo population decreased wallaby population decreased flora unaffected (C) dingo population increased wallaby population unaffected flora unaffected (D) wallaby population decreased flora increased insects and bird populations increased
QUESTION 3 (2 marks) Explain two ways that human activity can cause dryland salinity.
QUESTION 4 (9 marks) a) Using an example explain the concept of an ecological footprint. [3 marks] b) Using a case study discuss positive and negative human influences on the sustainability of ecosystems at local regional and global scales. [6 marks] Case study:
QUESTION 7 (5 marks) Two farmers received data that indicated that their properties were affected by salinity. Both farmers implemented salinity mitigation measures. Farmer A fenced off the area affected by salinity and sowed a mixture of tall grasses. Farmer B replanted a previously wooded hill area. Compare the two methods that the farmers used to combat their salinity problems and predict a probable outcome for each method.
QUESTION 8 (15 marks) Interpret the evidence in Stimulus 4 and Stimulus 5 in the stimulus book to draw a conclusion about the effectiveness of the salt interception scheme for sustaining the natural ecosystem that occurs along the Murray—Darling basin river system. Justify your conclusion.
QUESTION 10 Which anthropogenic factor would most likely affect the sustainable population of native biota? (A) changes to average seasonal rainfall (B) introduction of a new species for biological control (C) increased salinity in rivers through saltwater intrusion (D) planting of grass strips in agricultural systems to reduce erosion
QUESTION 7 (11 marks) This question refers to Stimulus 5—8 in the stimulus book. In January 2020 it was claimed that ‘management of the Namoi River catchment has had a negative impact on the availability and quality of fresh water in local ecosystems’. Water restrictions for general use in towns in the catchment area were implemented in December 2019 to increase the availability and quality of fresh water for local ecosystems. a) Draw aconclusion about whether the catchment has been managed effectively. Provide two reasons to support your conclusion. [3 marks] b) Discuss the claim made about the management of the catchment by using the stimulus to identify three possible causes and associated impacts on the local ecosystem. Propose and justify a solution to address the impacts. [8 marks]
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