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 7 of 17

1. Q6 · 2022 QCAA · Paper 2 · 5 marks
   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 Confidence Very Very Very Very Human In In high High Low low In hig…
   Functioning ecosystems and succession
2. Q7 · 2022 QCAA · Paper 2 · 6 marks
   QUESTION 7  (6 marks) The graph shows the population of bacteria in a Petri dish over time. 12 000 10 000 8000 Population 6000 4000 2000 0 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 populat…
   Biodiversity and populations
3. Q8 · 2022 QCAA · Paper 2 · 3 marks
   QUESTION 8  (3 marks) Over time, the South African cheetah population has suffered drastic reduction due to periodic droughts, disease and hunting. Currently, only small, isolated populations of cheetahs exist in the wild. Explain, in terms of genetic diversity, why cheetah populations are now on the verge of extinction.
   Continuity of life on Earth
4. Q9 · 2022 QCAA · Paper 2 · 3 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]
   Biodiversity and populations
5. Q10 · 2022 QCAA · Paper 2 · 3 marks
   QUESTION 10  (3 marks) In fruit flies, eye colour is a sex-linked trait inherited on the X chromosome. The red-eye allele (R) is dominant over the white-eye allele (r). A red-eyed male and white-eyed female have 50 offspring. Use a Punnett square to predict the number of male and female offspring and their eye colour.
   Genetics and heredity
6. Q11 · 2022 QCAA · Paper 2 · 8 marks
   QUESTION 11  (8 marks) Allele frequencies were monitored in two large populations of field mice from neighbouring forests over a 10-year period. Results are shown. Forest X Year Genotype Allele frequency AA Aa aa A a 2013 52 146 102 0.42 0.58 2014 48 144 108 0.40 0.60 2015 55 147 98 0.43 0.57 2016 60 150 90 0.45 0.55 2017 58 142 100 0.43 0.57 2018 58 148 94…
   Continuity of life on Earth
7. Q1 · 2021 QCAA · Paper 1 · 1 mark
   QUESTION 1 In mammals, inherited mutations can cause variations in the genotype of offspring when they occur in (A) red blood cells. (B) somatic cells. (C) nerve cells. (D) sex cells.
   Genetics and heredity
8. Q2 · 2021 QCAA · Paper 1 · 1 mark
   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.
   Functioning ecosystems and succession
9. Q3 · 2021 QCAA · Paper 1 · 1 mark
   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) The zooplankton are also able to photosynthesise. (B) Different phytoplankton species are preying on each other. (C) Car…
   Functioning ecosystems and succession
10. Q4 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 4 To demonstrate polygenic inheritance of colour in wheat, a cross was performed between two intermediate parents (AaBbCc × AaBbCc). Each dominant allele adds a ‘unit’ of colour to the phenotype. Which graph would depict the number of individuals and number of phenotypes for the cross? (A) (B) Number of individuals Number of individuals 1 2 3 4 5 6…
    Genetics and heredity
11. Q5 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 5 The graph shows changes for a penguin population and the theoretical carrying capacity of the environment. Carrying capacity A Time Point A on the graph indicates a change in carrying capacity triggered by (A) an increase in penguin pathogens. (B) a decrease in the number of mates available. (C) a reduction in space available for nesting sites.…
    Functioning ecosystems and succession
12. Q6 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 6 The pedigree traces a genetic disease across two generations. Generation I Key Carrier (not affected) Affected Normal Female Male Generation II The inheritance pattern of this disease can be classified as (A) incomplete dominant. (B) autosomal dominant. (C) sex linked. (D) polygenic.
    Genetics and heredity
13. Q7 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 7 In a long-term study of grasshopper colour in a grassland ecosystem, it was found that the most abundant phenotype changed from dark green to straw yellow. dark green straw yellow Population Phenotypic trait (colour) This change in the phenotype is an example of (A) diversifying selection. (B) directional selection. (C) stabilising selection. (…
    Continuity of life on Earth
14. Q8 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 8 The place where an organism lives is called its (A) niche. (B) habitat. (C) community. (D) environment.
    Biodiversity and populations
15. Q9 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 9 The image represents a gridded quadrat of 20 cm × 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 Species B Not to scale What is the approximate percentage cover of Species A? (A) 22% (B) 44% (C)…
    Biodiversity and populations
16. Q10 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 10 The forelimbs of humans, dogs, birds and whales have a very similar pattern of bones. Human Dog Bird Whale Not to scale The similarity of these structures is best explained by which pattern of evolution? (A) convergent evolution (B) divergent evolution (C) parallel evolution (D) coevolution
    Continuity of life on Earth
17. Q11 · 2021 QCAA · Paper 1 · 1 mark
    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
    Functioning ecosystems and succession
18. Q12 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 12 The phenotypic expression of genes is regulated by (A) transcription factors. (B) random fertilisation. (C) DNA polymerase. (D) helicase.
    Genetics and heredity
19. Q13 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 13 Which combination of processes demonstrates spermatogenesis? Where process occurs Outcome of process (A) testes one functional gamete with 2–3 polar bodies (B) ovaries four functional haploid gametes (C) testes four functional haploid gametes (D) ovaries one functional gamete with 2–3 polar bodies
    Genetics and heredity
20. Q14 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 14 Which event could cause a frameshift mutation? (A) non-disjunction during meiosis (B) error during replication (C) base pair substitution (D) heat damage
    Genetics and heredity
21. Q15 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 15 The table identifies the condition associated with a variety of ploidy changes. Chromosome number (ploidy) Condition name Monosomy 5 Cri du chat syndrome Trisomy 21 Down syndrome Trisomy 23 Klinefelter syndrome Monosomy 23 Turner syndrome For a person who has 45 chromosomes (2n–1) due to an autosomal condition, which condition do they have? (A)…
    Genetics and heredity
22. Q16 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 16 A small group of dingoes migrated to a new area and established a population. After several generations, the new population showed a different genetic composition from the original population. This is an example of (A) microevolution and gene flow. (B) macroevolution and gene flow. (C) microevolution and genetic drift. (D) macroevolution and…
    Continuity of life on Earth
23. Q17 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 17 This is a cladogram for seven different classes of organisms (I–VII). Class I II III IV V VI VII Which two classes of organisms are most closely related? (A) I and VII (B) IV and VI (C) I and II (D) III and IV
    Continuity of life on Earth
24. Q18 · 2021 QCAA · Paper 1 · 1 mark
    QUESTION 18 Which scenario would create a selection pressure on a given population? (A) change in fur colour (B) change in weather patterns (C) greater resistance to disease (D) improved ability to locate food sources
    Continuity of life on Earth