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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 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 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 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 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 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 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 22 (2 marks) Explain how two abiotic factors affect the distribution of species in an ecosystem. Ecosystem: Abiotic factor 1: Abiotic factor 2:
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 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 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]
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