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QUESTION 6 The carrying capacity of an ecosystem refers to the (A) total biomass of primary producers in the ecosystem at a given time that supports the higher trophic levels. (B) size of a population that can be supported indefinitely on the available resources and services of that ecosystem. (C) number of individual top predators in the ecosystem at a given time that can be supported by the lower trophic levels. (D) maximum population of individuals of different species that the ecosystem can support for an extended period of time.
QUESTION 7 When predicting successional change which of the following would typically indicate that an ecosystem is progressing toward its climax community? Abundance of K-selected species | Biomass
QUESTION 8 The table shows the daily energy input and output for a typical leaf. Incident sunlight Evaporation Heat loss (radiation) Reflection of sunligh Transmission of sunlight Calculate the daily net energy stored by the leaf. (A) 0.8kJ (B) 5.0kJ (C) 36.2kJ (D) 73.5kJ
QUESTION 9 The table provides population statistics for a species of tree kangaroo in northern Queensland. Determine the population growth rate for tree kangaroos in 2017. (A) 14.6% (B) 15.0% C) 26.5% (D) 86.9%
QUESTION 16 The figures show the original distribution zone of Species I and some possible distribution zones of Species I after the introduction of Species I1. Species II has a competitive advantage over Species I; however it does not tolerate areas of lower rainfall. Before After possible distribution zones ~ D removed from the ecosystem original distribution zone / Rainfall Rainfall Temperature Temperature Which of the following would be an accurate prediction of the new distribution zone for Species 1? (A) Zone A i.e. no change to the distribution (B) Zone B i.e. reduced distribution within the original zone (C) Zone C i.e. new distribution outside the original zone (D) Zone D i.e. complete removal of the species from the ecosystem
QUESTION 25 (4 marks) The following simplified energy-flow diagram provides the gross productivity figures for producers and herbivores in an ecosystem. plant respiration (including heat) herbivore respiration 16 MJ/m?/year 20 MJ/m?/year Producers i Higher CRESVQESS trophic levels decomposition decomposition 8 MJ/m?/year (waste and death/decay) 5 MJ/m?/year a) Determine the net productivity for the producers and herbivores in this ecosystem. [2 marks] Producers: Netproductivity=___ MJ/m?/year Herbivores: Net productivity=___ MJ/m?/year b) Contrast the outputs of energy for the two trophic levels in the diagram. [2 marks]
QUESTION 28 (4 marks) Identify two differences between primary and secondary ecological succession. Refer to one example of each type of succession in your response.
QUESTION 2 (5 marks) Two species of Paramecium single-celled microorganisms were grown for 4 days in test tubes with a fixed amount of algae added to each tube daily as their food source. The life span for each species ranges from 4—6 hours. Test tubes 1 and 2 each contained a single species and test tube 3 initially contained both species. Live Paramecium population after 4 days (per mL) T w0 T e s w0 a) Identify and describe the ecological principle that relates to these observations. [2 marks] b) Explain the results of the experiment. [3 marks]
QUESTION 6 (3 marks) The Bush Stone-curlew is a large mainly nocturnal ground-dwelling bird found on Hamilton Island. Bush Stone-curlews have a wide-ranging diet but prefer to feed on insects molluscs small lizards seeds and occasionally small mammals. During the breeding season nesting birds will search for food in the vicinity of the nest site. a) Identify one factor that would influence carrying capacity on the island. [1 mark] b) Discuss one way the carrying capacity of the Bush Stone-curlew on Hamilton Island could be positively or negatively affected in the future. [2 marks]
QUESTION 8 (3 marks) In an experiment studying the population dynamics of the house fly two adult house flies were placed in a fly cage with a limited food supply. Population data was collected as summarised in the table. Number of eggs Number of larvae | Number of pupae Number of adults -- Determine the population growth model exhibited by the house fly. Explain your reasoning.
QUESTION 2 The process of change in the species structure of an ecological community over time is known as (A) cyclic succession. (B) primary succession. (C) ecological succession. (D) secondary succession.
QUESTION 3 In ocean food webs where phytoplankton is in the first trophic level the second trophic level of zooplankton often has a higher biomass than the phytoplankton at any given time. Which explanation would account for this? (A) (B) © (D) The zooplankton are also able to photosynthesise. Different phytoplankton species are preying on each other. Carnivores in the third trophic level have increased their consumption of zooplankton. The phytoplankton multiply much faster than zooplankton but their lifespan is shorter.
QUESTION 5 The graph shows changes for a penguin population and the theoretical carrying capacity of the environment. A Carrying capacity Time Point A on the graph indicates a change in carrying capacity triggered by (A) an increase in penguin pathogens. (B) adecrease in the number of mates available. (C) areduction in space available for nesting sites. (D) an introduced disease affecting the penguins’ survival rates.
QUESTION 8 The place where an organism lives is called its (A) niche. (B) habitat. (C) community. (D) environment.
QUESTION 11 In which environment would primary succession occur? (A) fresh lava field (B) harvested wheat crop (C) grassland cleared by fire (D) forest damaged by a cyclone
QUESTION 20 A keystone species is defined as a species that (A) 1s the top predator in an ecosystem. (B) 1s a major producer in an ecosystem. (C) has a unique and crucial role in an ecosystem. (D) directly influences all species in an ecosystem.
QUESTION 22 (3 marks) Describe two ways carbon is transformed and one way it is transferred as it cycles through the biotic components of an ecosystem.
QUESTION 23 (5 marks) To determine the species diversity and species richness of a wetland ecosystem ecologists surveyed communities adjacent to a river using two methods for each community: 1. random species sampling with predetermined grid numbers with 10 quadrats of 4 m? each used for these grids 2. three belt transect lines (50 m X 2 m) across predetermined sampling locations based on strata variation. The map shows the locations of quadrats and transect lines. The table shows survey results. Key m River % Salt marsh Mangroves . Paperbark swamp ‘ Belt transect line [[] Quadrat Not to scale Survey method Belt transect Species richness (number of species) a) Identify three differences between the survey methods used to determine species diversity and species richness in the ecosystem. [3 marks] b) Draw a conclusion about the most suitable method for estimating species diversity and species richness of the communities in this wetland ecosystem. Give a reason to support your conclusion. [2 marks]
QUESTION 24 (5 marks) The diagram is a hypothetical biomass pyramid for a community. Secondary consumers 76 kg Primary consumers 1520 kg Producers 15200 kg Not to scale a) Contrast the efficiency of the biomass transfers between each level of the pyramid. [3 marks] b) Explain the difference in biomass transfer efficiency identified in Question 24a). [2 marks]
QUESTION 28 (3 marks) The graph depicts the population change of a species after it is introduced into a previously disturbed environment. Phase B Phase A Population size Time Referring to Phase A and Phase B determine the population growth model for the species.
QUESTION 1 (4 marks) Explain how one abiotic and one biotic factor will affect the population of mosquito larvae in a freshwater pond.
QUESTION 3 (3 marks) In coastal areas and deserts bare sand dunes may be colonised by plants such as members of the Poaceae family (grasses). Identify three features of these plants that make them effective colonisers.
QUESTION 13 (3 marks) The data shows changes in relative abundance of ground cover biomass and species diversity for an abandoned sand mine site over time. Key D Bare ground QGrasses (e.g. spinifex tussock grass) . Seedlings/shrubs (e.g. banksia eucalypt) Leaf litter I:] Mature trees Abundance Key D Biomass — Species diversity Biomass (kg/mz) Time Based on the information provided predict whether further ecological succession would occur in this community. Justify your answer with two relevant reasons.
QUESTION 5 A researcher captured marked and released 36 frogs. The following day they captured 24 frogs and 18 were marked. Calculate the approximate size of the frog population using the Lincoln index: N = Mnj (A) 27 (B) 48 (C) 54 (D) 60
QUESTION 7 What 1s used directly by plants for protein synthesis? (A) nitrite NO (B) mnitrate NOy~ (C) ammonia NH; (D) atmospheric nitrogen N
QUESTION 18 The competitive exclusion principle applies to different species occupying the same (A) niche. (B) habitat. (C) environment. (D) trophic level.
QUESTION 19 The graph shows the effect of light intensity on the germination success of seeds from four plant species. 100 . .......... Species I 80 g = 60 = < N — - Species II 40 O SN Species 111 201 T e . eec® eec® ...... . ) e . e Species IV Light intensity Which is most likely to be a pioneer species? (A) 1 (B) 1I (C) I (D) 1V
QUESTION 2 (4 marks) This 1s a biomass pyramid for a grassland community. Not to scale a) Calculate the percentage energy transfer between the first two trophic levels. Show your working. [2 marks] b) Explain the loss of biomass between trophic levels. [2 marks]
QUESTION 3 (4 marks) A glacier has retreated leaving a large amount of gravel small rocks sand and mud. a) Explain the steps of succession that would occur if the glacier continues to retreat. [3 marks] b) Identify the type of ecological succession. [1 mark]
QUESTION 4 (1 mark) Define keystone species.
QUESTION 6 (5 marks) An environmental report identified overexploitation habitat destruction and pollution as human activities affecting biodiversity in Australia. The tables show the estimated impact of each activity in 2011 and 2016. 2011 2016 Assessment grade Confidence Assessment grade Very Very H ac‘ggfiis high | High | Low | low high | High | Low impact 1mpact 1 pact 1 pact grade trend impact 1mpact 1 pact 1 pact grade trend Improving Very low impact: Few if any . Adequate: Adequate high- species and/or ecosystems are quality evidence and high level Getting worse suffering substantial adverse effects of consensus from this pressure E Biable Low impact: A small proportion Somewhat adequate: Adequate of species and/or ecosystems are high-quality evidence or high suffering substantial adverse effects level of consensus from this pressure High impact: A significant Limited: Limited evidence or proportion of species and/or limited consensus ecosystems are suffering substantial adverse effects from this pressure Very high impact: A large G Very limited: Limited evidence proportion of species and/or and limited consensus ecosystems are suffering substantial adverse effects from this pressure a) Explain how one human activity identified in the tables could reduce biodiversity. [1 mark] b) Predict which human activities will have the highest and lowest impact on biodiversity in 2023. Explain your reasoning using evidence from the tables. [4 marks] Highest impact: Lowest impact:
QUESTION 7 (6 marks) The graph shows the population of bacteria in a Petri dish over time. 12000 10000 8000 6000 Population 4000 2000 0 50 100 150 200 250 300 350 Time (minutes) a) Identify the mode of population growth. [1 mark] b) Determine the carrying capacity under these conditions. [1 mark] Conditions were modified at 380 minutes and the population continued to be monitored. Results are shown. 25000 20000 15000 Population 10000 5000 0 100 200 300 400 450 Time (minutes) c) Identify two modifications that could cause this change. Explain your reasoning. [4 marks]
QUESTION 3 In 1978 a population of a migratory shore bird was estimated at 90 000 individuals. An analysis of monitoring data in 2018 showed the population is now at 50 000. The change in population growth for this species is (A) —29% (B) —44% (C) —55% (D) —80%
QUESTION 4 This figure shows the relationship between spatial and temporal scale of drivers of ecosystem change. The size of the circles represents the proportion of drivers at a certain spatial scale that had a certain speed. very slow slow medium Temporal scale fast local national global Spatial scale Agricultural intensification along a river has led to substantial increases in fertiliser application and increases in stock numbers. From the given data predict the speed of ecosystem change along this river. (A) fast (B) medium (C) slow (D) very slow
QUESTION 8 Which feature makes pioneer species effective colonisers? (A) large seeds (B) slow-growth rate (C) shade-tolerant seedlings (D) ability to fixate nitrogen
QUESTION 14 This figure shows an energy pyramid for a hypothetical ecosystem. Decomposers Second order consumer = 16 276 kJ/m?/year = 201 kJ/m?/year First order consumer = 2494 kJ/m?/year Primary producers = 36 380 kJ/m?/year The trophic level transfer efficiency of primary producers to herbivores in this situation would be (A) 0.6%. (B) 6.9%. Q) 7.4%. (D) 44.7%.
QUESTION 15 The figure below shows a model of two species populations species A and species B competing for the same resource over time. 160 140 Species A — - N o Species B 100 Population density Qo o Time (dimensionless) Identify the response that describes the relationship between the two species over time. (A) species A competitively excludes species B (B) species B competitively excludes species A (C) there is no competitive exclusion coexistence occurs between species (D) either species competitively excludes the other based on population densities
QUESTION 17 Which of the figures below represents a logistic population growth of a species over time? (A) Population Time (B) Population Time ©) Population Time (D) Population Time
QUESTION 25 The table below shows the probability of the replacement of one individual tree by another of the same or different species in 50 years’ time. Occupant in 50 years Present occupant Grey birch Red maple Blackgum Beech Red maple 0.00 0.53 0.14 0.31 Blackgum 0.01 0.25 0.57 0.17 Which species is most likely to replace grey birch in a 50-year temporal successional change in this forest? (A) grey birch (B) red maple (C) Dblackgum (D) beech
QUESTION 28 (5 marks) The figure below shows a model of ecological niche occupation by species A—E. : T :_¢§ Species D - ‘© 2 | ® % © . m = 2 Z 2 3 Cool Warm Niche axis 2 — Temperature a) Identify which two species are occupying the same ecological niche. [1 mark] b) Species A and B have a common ancestor. Which diversification pattern would have occurred between species A and species B for them to occupy these niches? [1 mark] The table below shows the frequencies of genotypes and phenotypes for a particular trait in a generation of species E. Genotype (% frequency) Phenotype (% frequency) TT (0) Tt (100) tt (0) Phenotype 2 (0) c) Predict the next generation’s genotype and phenotype frequency. Which type of inheritance pattern is represented for Phenotype 17 Phenotype 1 (100) [3 marks]
QUESTION 29 (6 marks) The diagram below shows fossilised marine organisms found in a site across seven stratum layers. 27 1l (S ’@ ek N b e %\}? 7 a) Analyse the data above to identify three relationships that provide evidence of changes in past ecosystems. Identify at least one biotic change and at least one abiotic change. b) From the given information determine the species richness (D) for strata 2. Use the following formula: S =T Where s= the number of different species represented in the sample and N = the total number of individual organisms in the sample c) Identify one limitation of using fossil evidence to determine species richness.
QUESTION 30 (6 marks) The figures below show a forest before harvesting (pre-harvest) and after harvesting (post-harvest). Pre-harvest ' Post-harvest Identify an ecological surveying technique and sampling method that could be used to effectively analyse the change in species diversity between the two ecosystems. Identify a strength and a limitation of each of your choices.
QUESTION 3 The table provides population data for a species of fairy-wren. Year Population on Births Deaths Immigration | Emigration 1st January 2022 15200 200 7600 | 4310 | The population growth rate in 2022 was closest to (A) 17% (B) 27% (C) 55% (D) 73%
QUESTION 9 An ecological niche refers to (A) a group of organisms competing for the same resources. (B) the role and space that an organism fills in an ecosystem. (C) all organisms occupying a physical space close enough to interact with each other. (D) the largest population of a particular species that can be supported by an ecosystem.
QUESTION 10 The graph shows extinction rates over time. a ee NO) PPD PS 107 Extinction rate (families per million years a a re 500 450 400 350 300 250 200 ©1506 6100 8§©650 0 Millions of years ago (Mya) How many times in the past 500 million years has the extinction rate exceeded 14 families per million years? (A) 3 (B) 4 (C) 5 (D) 6
QUESTION 14 An energy pyramid for an aquatic ecosystem is shown (values are in kJ m secondary consumers 410 primary consumers 3400 producers 21 600 Transfer efficiency between producers and primary consumers is closest to —2 y’). Not to scale (A) 5% (B) 10% (C) 12% (D) 16%
QUESTION 20 The capture—recapture method and Lincoln index (N = ant) were used to monitor a population of m platypuses over a four-year period. Experimental findings are shown. 26 24 22 20 18 16 14 Number of platypuses 2019 2020 2021 2022 Year The table shows data from one year of the study. Number of individuals captured and marked in first sampling Number of individuals captured in second sampling Number of recaptured individuals marked When was the data in the table collected? (A) 2019 (B) 2020 (C) 2021 (D) 2022
QUESTION 22 (2 marks) Describe two ways bacteria assist matter to cycle through ecosystems.
QUESTION 26 (3 marks) Wedge-tailed eagles are large birds that reside in tall trees where they build nests for their young. They often feed on ground-dwelling herbivores such as kangaroos and rabbits. The graph shows the number of wedge-tailed eagles observed in an ecosystem over time. 800 700 | Sf | | 600 LAY ! [ 300 200 / : 3 : 100 : 0 2010 2012 2014 2016 2018 2020 2022 Number of eagles Year a) Determine the carrying capacity of wedge-tailed eagles in this ecosystem. [1 mark] b) Explain how a change to one abiotic factor could reduce the carrying capacity. [2 marks]
QUESTION 2 (4 marks) The diagram shows feeding relationships for an Australian ecosystem. a) Use the data to explain why dingoes are a Keystone species. [2 marks] b) Predict the effect a drastic reduction in the number of dingoes would have on the termite population. Justify your response. [2 marks]
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Paper 2
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2023
QUESTION 7 (5 marks) The diagram shows the stages of succession in an ecosystem. Stage 1 Stage 2 Stage 3 Bare rock Lichen and Trees and shrubs herbaceous plants Time Stage 4 Mature forest a) Identify the type of ecological succession depicted. Explain your reasoning. b) Infer two features of the species in stage 2 and describe the role of these species in ecological succession. [2 marks] [3 marks]
QUESTION 9 (7 marks) The graphs show the findings of an experiment investigating the competitive exclusion principle. Two species of protozoa (P. aurelia and P. caudatum) were grown separately and together under identical conditions. Grown separately Grown together 300 250 300 250 P. aurelia lia N S o N S Oo one sens seni e deen esce cesses sees ous sere serenrenbennnaeesnewesuaed 150 100 100 50--—/ 2s = -- P caudatum Population density (cells/mL) a S Population density (cells/mL) 50 Fe i a o+ P. caudatum 0 5 10 15 20 10 20 Time (days) Time (days) a) Identify the population density of P caudatum on day 10 when grown separately. [1 mark] b) Compare the growth of P. aurelia in the two graphs. [3 marks] c) Use the data to explain the competitive exclusion principle. [3 marks]
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