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QUESTION 4 The following information includes: » akey that is used to classify the types of alpine and subalpine grassland habitats « atable of abiotic and biotic data obtained from a habitat survey. Alpine and subalpine grasslands Habitat classification Moss-and-lichen- Yes — dominated mountain summit Alpine and subalpine Yes —> nutrient-enriched grassland Calcareous alpine and Basic — subalpine grassland Acidie — Adcidicalpine and subalpine grassland Abiotic physical parameter Reading Reference range for nutrient-poor soil (mg/kg) Nitrates/nitrites (mg/kg) Ammonia (mg/kg) Total phosphorous Biotic description: Small amount of low-lying moss growing on soil substrate. Predominantly low-lying grasses. Using the data in the table and the key this alpine and subalpine grassland would be classified as (A) amoss-and-lichen-dominated mountain summit. (B) an alpine and subalpine nutrient-enriched grassland. (C) acalcareous alpine and subalpine grassland. (D) an acidic alpine and subalpine grassland.
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 11 The Linnaean system originally used which type of evidence for classifying organisms? (A) physical features (B) common ancestry (C) molecular phylogeny (D) reproduction methods
QUESTION 14 One of the common assumptions in cladistics is that (A) (B) ©) (D) not all organisms are related by descent. the characteristics of organisms in a population stay the same over time. new kinds of organisms may arise when existing populations divide into two groups. the more shared characteristics two organisms have the more closely related they are.
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 19 The table of data shows a comparison of amino acids sequences in the same section of haemoglobin molecules from a number of different species. From the given information which of the following species’s haemoglobin protein is most similar to human haemoglobin protein? Species ’ Sequence of amino acids | Ly | Go | b | B | | Go o oL [ o [ o o
QUESTION 21 (2 marks) A count was conducted to determine the number of individuals for five different bird species in a woodland. 55 50 2 45 Cg S 40 '% 35 g 30 S 25 g 20 O g 15 Z 10 5 0 A C D Species Calculate the relative percentage abundance of species B. Show your working.
QUESTION 22 (4 marks) The following cladogram proposes the evolutionary history of several fish phyla (A—H). A B C D B F G H a) Define the term clade. Circle an example of a clade on the cladogram. [2 marks] b) Which node (1-7) represents the most recent common ancestor for species E and G? [1 mark] c¢) Which two species shared the most recent common ancestor? [1 mark]
QUESTION 23 (3 marks) Describe differences between r-selected and K-selected species in terms of: * number of offspring parental care and involvement * lifespan. r-selected K-selected Number of offspring Parental care and ivolvement Lifespan
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 1 (4 marks) a) Explain how a species interaction may be classified as symbiotic. [2 marks] b) Using an example describe the symbiotic relationship of mutualism. [2 marks]
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 4 (6 marks) An ecologist investigated the species composition of mangrove trees in a natural mangrove forest and an adjacent 30-year-old planted mangrove forest. Three 10 m-wide belt transects were sampled from inland to the sea for each of the forests each covering 100 m on average and placed to cover various strata. The species diversity of Forest A was determined using the Simpson’s Diversity Index (SDI): L B0 WV 7 e | 0|5 ommgoe |5 |0 a) Use the SDI formula to calculate the diversity index for Forest B. Round your answer to two decimal places. [2 marks] b) Identify three reasons why the ecologist used a belt transect rather than line transects or randomly placed quadrats for collecting data to compare these two forests. [3 marks] c) Identify one way in which the ecologist minimised bias in the sampling. [1 mark]
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 7 (4 marks) Species richness (S) can be determined using the Menhinick’s Index where s is the number of different species represented in a sample and N is the total number of individual organisms in the sample. Species richness (S) = _al JN Sampling of two communities (Community A and Community B) were completed with Community A having S = 0.5 for the six species identified. The results for Community B are shown in the table. Community B e s s [ w Use S to compare Community A with Community B.
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 9 The image represents a gridded quadrat of 20 cm X 20 cm squares used in a plant survey. To calculate cover for a species the surveyor identified each plant species and then counted the number of squares in which the species appeared. Key {% Species A i Species B Not to scale What is the approximate percentage cover of Species A? (A) 22% (B) 44% ©) 53% (D) 58%
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 17 This is a cladogram for seven different classes of organisms (I-VII). Class IT III IV VI VII Which two classes of organisms are most closely related? (A) Tand VII (B) IV and VI (C) TandII (D) IIland IV
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 21 (4 marks) In the Linnaean system of classification the features used to classify living things change according to taxonomic levels. Describe using relevant examples how these features change.
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 6 (2 marks) The term species could be defined as ‘one group of individuals that actually or potentially interbreed 1n nature’. Identify two limitations of this definition.
QUESTION 12 (5 marks) An investigation compared mangrove species diversity for two areas of different size in the same catchment. The table shows species population counts for each area. Grey mangrove Red mangrove Yellow mangrove 88 (? Total species count a) Calculate Simpson’s diversity index for Area 2. Show your working. SD]_I_[M N(N —1) (correct to two decimal places) b) Using your answer for Question 12a) compare the diversity of the two areas. [2 marks] [3 marks]
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 3 A survey of grasshopper species was conducted across four eucalypt communities. Counts were conducted and the average abundance per 400 m? recorded. Grasshopper species (A-F) ) S N Which community has both the highest species richness and highest evenness for grasshoppers? (A) 1 (B) II (©) I (D) 1V
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 8 The graph shows how the populations of two species in an ecosystem change over time. Key Species X ---- Species Y 9] 5 . p— c < &0 — o (A 8 l/ \ O / \ O / \ g / \ B / \ Z JER / \ ’ / \ / Y / \ / \ / \ / \ / \\ / / )/ . / 1 277G 7 \ /l —s\\ ’ / \\— N - \\ ’ ~ Time Which species interaction is represented? (A) predation where species X preys on species Y (B) predation where species Y preys on species X (C) competition where species X outcompetes species Y (D) competition where species Y outcompetes species X
QUESTION 11 Evolutionary relationships were investigated by sequencing a section of protein from five different species. Each letter represents an amino acid. Species I D Species 11 D Species I11 D Species IV D Species V D It can be inferred that Species I 1s most closely related to (A) Species II. (B) Species III. (C) Species IV. (D) Species V.
QUESTION 16 If each shape represents a different species which diagram shows the common assumptions of cladistics? (A) ] (B) /\ 0 0 ] /\ Time Time (®) A (D) D - h 3 O A\ Time Time
QUESTION 17 Students used quadrats to investigate biodiversity in a grassland community with scattered distribution of plant species. The students agreed on a counting criteria for each quadrat to (A) reduce the time taken to count the different species. (B) minimise statistical uncertainty. (C) ensure all strata were sampled. (D) minimise bias.
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 21 (2 marks) Describe two reproductive strategies used to distinguish K-strategists from r-strategists. Strategy 1: Strategy 2:
QUESTION 22 (2 marks) Explain how two abiotic factors affect the distribution of species in an ecosystem. Ecosystem: Abiotic factor 1: Abiotic factor 2:
QUESTION 24 (2 marks) Explain two ways that classifying ecosystems allows for effective management of old-growth forests.
QUESTION 25 (4 marks) Severe weather events have caused widespread loss of seagrass in meadows off Location A. Seagrasses have the capacity to recover from weather-associated disturbances and return to pre-impact levels within 4 to 60 months. Deep-water meadows have a higher rate of recovery than shallow-water meadows. o Location A Key B Shallow-water meadows [ Deep-water meadows D Sea 0 25 B Land ; L} Lan Kilometres Describe how stratified sampling could be used to study how seagrass meadows off Location A recover after a severe weather event. Identify a surveying technique and purpose for the study in your response.
QUESTION 1 (3 marks) This phylogenetic tree uses horizontal distance to represent genetic difference. Species A Species B Species C Species D L 1 unit Scale 1 unit = nucleotide difference a) Infer which species is most closely related to species B. Explain your reasoning. [2 marks] b) Determine the genetic difference between species A and D. [1 mark]
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 9 (3 marks) The biological species concept defines species as a group of organisms that can interbreed to produce fertile offspring. a) Identify another method for defining a species. [1 mark] b) Describe one limitation of the biological species concept and one limitation of the method identified in Question 9a). [2 marks]
QUESTION 1 Female Komodo dragons (Varanus komodoensis) in the absence of a mate can produce offspring in which the growth and development of the embryo can occur without the joining of gametes. Identify which of the following methods of reproduction would be used to classify this species. (A) Dbinary fission (B) parthenogenesis (C) internal fertilisation (D) external fertilisation
QUESTION 2 An investigation surveyed a land zone that had ¢ high precipitation rates e an open canopy forest with tall emergents and e a well-developed understorey of ferns palms and sclerophyll shrubs. The dominant forest tree species were e flooded gum (Eucalyptus grandis) e Sydney blue gum (Eucalyptus saligna) e red mahogany (Eucalyptus resinifera) and e brush box (Lophostemon confertus). A dominant vegetation community classification system would classify this ecosystem as a (A) rainforest. (B) eucalypt woodland. (C) eucalypt open forest. (D) wet eucalypt open forest.
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 12 Which symbiotic interaction occurs when one species is harmed and the other species benefits? (A) parasitism (B) mutualism (C) amensalism (D) commensalism
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 1 The biological species concept defines species as a group of organisms (A) with a common set of alleles. (B) descended from a common ancestor. (C) occupying the same niche or adaptive zone. (D) that can interbreed to produce fertile offspring.
QUESTION 2 Species classified as K-strategists (A) often live in unstable habitats. (B) exhibit an exponential rate of reproduction. (C) reach sexual maturity later than r-strategists. (D) are first to colonise a new environment created by a disturbance.
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 12 The graph shows the results of a study on the species richness of gut microbes. The data represents the cumulative number of species observed as the number of samples increased. 800 700 600 500 400 300 Number of species 200 100 8 10 12 14 16 Number of samples Based on this data the minimum number of samples required to obtain valid species richness data is (A) 2 (B) 6 (C) 12 (D) 16
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 23 (3 marks) Mistletoe is the common name for plants that have a close and long-term interaction with a host tree. In Australia mistletoe frequently live on eucalyptus trees penetrating the bark with their modified root systems to access water and nutrients from the xylem. This can restrict nutrient flow in the host tree and may cause parts of its branches to die. a) Identify the species interaction demonstrated in this scenario. [1 mark] b) Explain how this relationship differs from predation. [2 marks]
QUESTION 25 (6 marks) The effect of an invasive species on plant biodiversity was investigated by collecting this data from an ecosystem. Percentage cover (invasive species) 0-20% >20-40% | >40-60% | >60-80% | >80-100% Species richness Simpson’s diversity index a) Contrast species richness in areas of low invasive species cover (0O—20%) with areas of high invasive species cover (>80—100%). [1 mark] biodiversity b) Draw aconclusion about the effect of the invasive species on plant biodiversity in this ecosystem. Justify your response. [2 marks] c) Explain why having data on species richness and Simpson’s diversity index is more informative than a single measure for the purpose of this investigation. Refer to the table to support your response. [3 marks]
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]
![Question-Image](https://examinsightsimages.syd1.cdn.digitaloceanspaces.com/Biology/Biology_2023_Paper_2_Question_2.webp)
Difficulty: A
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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]
QUESTION 5 (3 marks) Nucleic acid sequences were used to investigate evolutionary relationships between four species. Species Nucleic acid sequence GACCGCATTTACGTA GACGTCATATCCGTA a) b) GACCGCATTTCCGTA GACGGCATATCCGTA Explain how data from conserved molecular sequences can be used to estimate time since divergence. Use the data to infer species I-IV in the cladogram. Species Species Species Species I: B. bartonus II: [2 marks] [1 mark] Il:
QUESTION 1 (6 marks) The profile diagram shows a representative section of an ecosystem. Height (m) Distance (m) This table can be used to classify ecosystems based on Specht’s classification system. Foliage cover of tallest plant layer Dense (70—100%) Mid-dense (30—70%) | Sparse (10-30%) Tall closed-forest Tall open-forest Tall woodland Closed-forest Woodland Low closed-forest Low woodland Closed-scrub Tall shrubland Classify this ecosystem. [1 mark] Describe how field data could be collected for the purpose of classifying this ecosystem using Specht’s classification system. Include at least one strategy to minimise bias. [3 marks] Explain how Specht’s classification system could be used to monitor how the ecosystem recovers after a logging event that removes 80% of trees from the tallest plant layer. [2 marks]
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