QCEVault

Biology questions and solutions

Browse original practice and official past-paper questions. Each question has its own link, with its source and worked solution.

385 questions · Page 10 of 17

  1. Q26 · 2020 QCAA · Paper 1 · 1 mark
    QUESTION 26  (1 mark) Define microevolution.
    Continuity of life on Earth
  2. Q27 · 2020 QCAA · Paper 1 · 4 marks
    QUESTION 27  (4 marks) In a freshwater lake in Africa, a species of crab and its snail prey species both exhibit specialisations that are unusual for freshwater species. The crabs possess strong claws with characteristics of marine crabs that crush and peel shells, and the snail prey have thick, strong shells that resist crushing. a) Identify which pattern…
    Continuity of life on Earth
  3. Q28 · 2020 QCAA · Paper 1 · 4 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.
    Functioning ecosystems and succession
  4. Q1 · 2020 QCAA · Paper 2 · 4 marks
    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]
    Functioning ecosystems and succession
  5. Q2 · 2020 QCAA · Paper 2 · 5 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 Parameci…
    Functioning ecosystems and succession
  6. Q3 · 2020 QCAA · Paper 2 · 4 marks
    QUESTION 3  (4 marks) Explain the role of the enzymes helicase and DNA polymerase in the process of DNA replication.
    Genetics and heredity
  7. Q4 · 2020 QCAA · Paper 2 · 6 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 Fore…
    Biodiversity and populations
  8. Q5 · 2020 QCAA · Paper 2 · 4 marks
    QUESTION 5  (4 marks) Explain the process of protein synthesis in terms of transcription and translation.
    Genetics and heredity
  9. Q6 · 2020 QCAA · Paper 2 · 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)…
    Biodiversity and populations
  10. Q7 · 2020 QCAA · Paper 2 · 4 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. s Species richness (S) = N Sampling of two communities (Community A and Community B) were completed, with Community A having S = 0.5 for t…
    Biodiversity and populations
  11. Q8 · 2020 QCAA · Paper 2 · 3 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. Generation Number of eggs Number of larvae Number of pupae Number of adults 1 0 0 0 2 2 120 110 95 88 3 250 225 213 210 4 500 475 462 1…
    Biodiversity and populations
  12. Q9 · 2020 QCAA · Paper 2 · 3 marks
    QUESTION 9  (3 marks) Fossil evidence seems to show that the morphology of the Queensland lung fish has remained relatively unchanged for the past 100 million years. Describe the features of the theory of natural selection to explain how this may have occurred.
    Continuity of life on Earth
  13. Q10 · 2020 QCAA · Paper 2 · 3 marks
    QUESTION 10  (3 marks) Researchers measured the adult beak lengths of an entire population of a species of bird and plotted their results on the graph. After many generations, the lengths of the adult beaks were again measured. By comparing this new data to the original data, the researchers concluded that the average length of beaks had increased as a resul…
    Continuity of life on Earth
  14. Q11 · 2020 QCAA · Paper 2 · 6 marks
    QUESTION 11  (6 marks) The image shows changes in the frequency of a particular gene in a single species of bird, leading to a speciation event. These changes have occurred over a period of successive time points (i.e. I, II and III) each separated by approximately 1000 generations. • The letters A, B, C and D represent separate niches inhabited by the bird…
    Continuity of life on Earth
  15. Q1 · Original practice · 1 mark
    Which observation identifies a limitation of the biological species concept?
    Biodiversity and populations
  16. Q2 · Original practice · 1 mark
    A ranger marks and releases 48 freshwater turtles. After the marks have mixed through the population, 60 turtles are caught; 12 are marked. Using the Lincoln index, the estimated population size is
    Biodiversity and populations
  17. Q3 · Original practice · 1 mark
    A sample contains 10 individuals of species A and 10 of species B. Use SDI=1−∑n(n−1)N(N−1)SDI=1-\dfrac{\sum n(n-1)}{N(N-1)}. Its Simpson’s diversity index is closest to
    Biodiversity and populations
  18. Q4 · Original practice · 1 mark
    A grass species occurs in 9 of 15 quadrats. What is its percentage frequency?
    Biodiversity and populations
  19. Q5 · Original practice · 1 mark
    Use the dichotomous key to identify an organism with no wings and eight legs.
    Biodiversity and populations
  20. Q6 · Original practice · 1 mark
    The graph shows a population growing in a closed habitat. Which explanation best accounts for the shape after day 10?
    Biodiversity and populations
  21. Q7 · Original practice · 1 mark
    A community’s tallest stratum consists of 18 m trees with 45% foliage projective cover. Using the supplied Specht classification excerpt, classify the community.
    Biodiversity and populations
  22. Q8 · Original practice · 1 mark
    A population initially contains 400 lizards. During one month there are 55 births, 32 deaths, 18 immigrants and 21 emigrants. Its net change is
    Biodiversity and populations
  23. Q9 · Original practice · 1 mark
    A wetland has gross primary productivity of 2400 kJ m−2 year−12400\ \mathrm{kJ\,m^{-2}\,year^{-1}} and producer respiration of 900 kJ m−2 year−1900\ \mathrm{kJ\,m^{-2}\,year^{-1}}. Its net primary productivity is
    Functioning ecosystems and succession
  24. Q10 · Original practice · 1 mark
    In a pond, producers store 18000 kJ in new biomass during a month. Primary consumers store 1800 kJ and secondary consumers store 144 kJ. The transfer efficiency from primary to secondary consumers is
    Functioning ecosystems and succession