Chapter 4: Evolution of Australian biota (30 questions)
1. Scientific evidence that supports the assertion that Australia was once part of a land mass called Gondwana, includes:
  Hint

    a) matching continental margins.
    b) position of mid-ocean ridges.
    c) spreading zones between continental plates.
    d) fossils in common on Gondwanan continents including Glossopteris and Gangamopteris flora and marsupials.
    e) all of the above.



2. Studies of residual magnetism have shown that in the past 171 million years, the Earth’s magnetic field has reversed 71 times. The significance of this observation is that it provides evidence to support:
  Hint

    a) plate tectonic theory.
    b) the age of the Earth.
    c) the jigsaw fit of all continents.
    d) evolution.
    e) natural selection.




3. Zones where the crust is being destroyed are called:
  Hint

    a) mid-ocean ridges.
    b) plate margins.
    c) constructive plate boundaries.
    d) subduction zones.
    e) transform boundaries.





4. Wet and dry sclerophyll forests usually occur in:
  Hint

    a) regions where the rainfall is highest and the daily temperature range is narrow.
    b) moderate to high rainfall areas that are usually not as wet as rainforest.
    c) large areas along the west of the Great Dividing Range in New South Wales and Victoria.
    d) areas with high temperatures and erratic rainfall.
    e) the driest and hottest regions of the interior.



5. An ecosystem has the following characteristic biological features: A mid-dense to dense canopy (10–70%), where the tallest plants are shrubs, such as acacias, casuarinas or melaleucas reaching a height of (2–5 m). Vegetation is usually dense and tangled, often with a ground cover of grasses. This ecosystem would most probably be named a/an:
  Hint

    a) rainforest ecosystem
    b) woodland ecosystem.
    c) scrub ecosystem.
    d) wet sclerophyll ecosystem.
    e) arid grassland ecosystem.



6. The historical development of Australia’s unique flora and fauna shows evidence of evolution on a massive scale. Natural selection worked on the variation within a species, favouring organisms that were able to survive to reach reproductive maturity. One example of this development for plants was:
  Hint

    a) the arrival of Aborigines in Australia selectively eating particular plant types for food.
    b) increasing frequency of fire and the growth of fire-sensitive forests such as Podocarpus.
    c) the increase in acacias and banksias that could compete effectively in poor soils.
    d) the decline in beech forests as Australia continued to become drier.
    e) the drier regions of the interior becoming richer in dry sclerophyll forests.



7. Adaptive radiation can be defined as:
  Hint

    a) the spreading of organisms into new habitats and their subsequent evolution through adaptation to suit the environments they inhabit.
    b) the evolution of a variety of specialised kinds of organisms from a primitive, relatively unspecialised ancestor.
    c) the evolution of separated populations in their sometimes different habitats.
    d) the development of a population that seems to have arisen by chance.
    d) the survival and reproduction of organisms that were advantaged with favourable variations.



8. According to the Therian hypothesis:



  Hint


    a) mitochondrial DNA of marsupials and monotremes is more alike.
    b) marsupials and monotremes have a closer evolutionary relationship than placentals and marsupials.
    c) DNA sequences indicate that marsupials are more closely related to placentals than monotremes.
    d) marsupials and placentals are more closely related than marsupials and monotremes.
    e) it is not possible to show any evolutionary relationships between monotremes and placentals.



9. Numerous studies to determine the evolution of the platypus supports the general understanding that:
  Hint

    a) ideas in science continue to develop as scientific evidence accumulates.
    b) it is not possible to show any evolutionary relationships between monotremes and placentals.
    c) scientists cannot agree on the origins of the platypus and probably never will.
    d) marsupials and placentals are more closely related than marsupials and monotremes.
    e) natural selection shows that marsupials are more closely related to placentals than monotremes.



10. The following skeleton is the largest of the megafauna organisms and is now extinct. This organism was:



    Hint

    a) a giant marsupial predator.
    b) thought to be a giant herbivore.
    c) thought to be a giant carnivore.
    d) similar to the modern-day kangaroo.
    e) similar to a dingo.



11. A method of asexual reproduction that occurs when an unfertilised egg grows into a new organism is:
    Hint

    a) binary fission.
    b) vegetative propagation.
    c) parthenogenesis.
    d) fusion.
    e) somatism.



12. In the table, the letters A and B represent the speed and complexity of each type of reproduction type.
Asexual Sexual
  • Involves only one parent
  • Involves one or two parents
  • Involves mitosis (cell division)
  • Involves mitosis and meiosis
    (reduction cell division)
  • Does not involve fertilisation
  • Involves fertilisation
  • Offspring are carbon copies or clones of the parent
  • Offspring are not clones of the parents but show new combinations of characteristics
A B
  • Confers no variation on the offspring, which is limiting in cases of environmental change or in cases of passing on defects
  • Produces variation in the offspring, which can be an advantage in cases of environmental change where it is likely that some individuals can survive in the new environment or in cases of passing
  • Useful in plant breeding where identical offspring are required
  • Useful in breeding where variety is sought


The best description for labels A and B would be:
    Hint

    a) A (sexual) is less complex, quicker but uses more energy, while
               B (asexual) Is simple and quick.
    b) A (asexual) is simple, while B (sexual) is more complex.
    c) A (asexual) is simple and quick, while B (sexual) is more complex, slower and uses more energy.
    d) A (asexual) is slow but simple, while B (sexual) is more complex, slower and uses more energy.
    e) A (sexual) is more complex, slower and uses more energy, while B (asexual) Is simple and quick.



13. To keep the number of chromosomes constant from one generation to the next in a species, it is essential that the number be halved before fertilisation takes place. The process by which this reduction takes place is known as:
    Hint

    a) gene splicing.
    b) meiosis.
    c) mitosis.
    d) somatism.
    e) fusion.



14. When comparing daughter cells produced in mitosis and meiosis:
     Hint

    a) in meiosis, daughter cells are identical to the parent cell and become somatic cells, whereas in mitosis, daughter cells are gametes that are identical                to the original parent cell.
    b) in mitosis, chromosome numbers in the daughter cells are half of those in the parent cell, whereas in meiosis, daughter cells are gametes that are                identical to the original parent cell.
    c) in mitosis, daughter cells are identical to the parent cell and become somatic cells, whereas in meiosis, daughter cells are gametes that are in which                chromosome numbers are the same as the parent cell.
    d) in mitosis, daughter cells are identical to the parent cell and become somatic cells, whereas in meiosis, daughter cells are gametes that are not                identical to the parent cell.
    e) all of the above are false.



15. Which of the following aspects of asexual reproduction are correct?
    Hint

    a) The offspring are identical to the parents.
    b) Mitosis or cell division occurs.
    c) There is much less variation.
    d) Any variation that occurs is due to mutation.
    e) All of the above are correct.



16. The fusion of gametes in fertilisation results in the formation of a new cell, which may develop inside or outside of the female. This ‘first cell’ of the new organism is called a/an:
     Hint

    a) gamete.
    b) zygote.
    c) offspring.
    d) morula.
    e) spore.



17. Which of the following choices summarises some of the features of internal fertilisation?
     Hint

    a) Common in land plants, reptiles, birds and mammals. Male gametes are shed into a confined space, resulting in a greater chance of fertilisation.
    b) Common in fish, amphibians and algae. The zygote can be retained inside the female’s body for protection until it is fully developed.
    c) Copulation occurs and male gametes are shed into a large space. The zygote usually develops outside male and female parents.
    d) Common in land plants, reptiles, birds and mammals. Many male and female gametes are shed into a confined space for improved chance of                fertilisation.
    e) Common in fish, amphibians and algae. The zygote usually develops outside male and female parents.



18. When describing the reproductive adaptations of the kangaroo, which of the following options represents embryonic diapause?
   Hint

    a) When the female mates with different males, giving her offspring greater genetic diversity and increasing the likelihood of surviving in a changing                environment.
    b) Males and females mate with very few partners but invest a lot of energy in ensuring the survival of the offspring.
    c) A process where the second embryo is held in storage until the fetus in the pouch reaches a level of development where it leaves the pouch.
    d) The fetus is held in the pouch until it reaches a safe level of development for survival.
    e) The fertilised embryo stops developing because conditions are harsh, and is held in this state of storage until conditions improve.



19. A process whereby the parent plant releases substances into the soil that inhibit seed germination close to the adult plant is known as:
    Hint

    a) inhibition.
    b) allelopathy.
    c) pollination.
    d) competition.
    e) dispersal.



20. A reproductive adaptation in some plants is the triggering of germination by high concentrations of potassium produced by ash after fire. This would provide the seeds of these plants with an advantage because:
  Hint

    a) they can readily germinate and use the enriched soils to establish themselves before other plants after a fire.
    b) the soil is usually more easily penetrated by the seedlings after a fire, increasing the chances for success.
    c) it is likely to rain after a bushfire, making it easier for the seeds to germinate and establish themselves.
    d) there is the possibility that the seedlings will reach maturity faster than other plants.
    e) the seedlings produced are not burnt in any subsequent fire.



21. During this topic, you may have designed an experiment to investigate the germination of seeds. What would you need to do to ensure the reliability of the investigation?
    Hint

    a) Repetition (doing more trials) to ensure the trustworthiness of the results, and the elimination of random errors.
    b) Ensure that only the effects of the independent variable(s) on the dependent variable (variable of interest) are measured, with all other variables held                constant.
    c) Assess any systematic errors associated with the experimental set-up.
    d) Consider how confident you are about the conclusions drawn from the results of the investigation.
    e) Check to see if you have a faulty measuring device, which could consistently provide a wrong value.



22. During this topic, you may have designed an experiment to investigate the germination of seeds. What would you need to do to ensure the validity of the investigation?
     Hint

    a) Repetition (doing more trials) to ensure the trustworthiness of the results, and the elimination of random errors.
    b) Ensure that only the effects of the independent variable(s) on the dependent variable (variable of interest) are measured, with all other variables held                constant.
    c) Assess any systematic errors associated with the experimental set-up.
    d) Consider how confident you are about the conclusions drawn from the results of the investigation.
    e) Check to see if you have a faulty measuring device, which could consistently provide a wrong value.



23. It is advantageous for plants of the one species to spread over a wide area:
    Hint

    a) to prevent any unnecessary competition between other plants, that may result in the loss of a species not widely distributed.
    b) because the species is more likely to survive such dangers as disease, fire or environmental change, and the entire population is less likely to be                wiped out.
    c) because parent plants do not like their offspring too close to themselves, as the animals that feed on them may increase in numbers.
    d) because they do not need to rely as much on the one type of organism to assist with pollination
    e) because wind pollination mechanisms are not suitable in all areas.



24. Sex cells, more correctly known as gametes:
    Hint

    a) contain all of the genetic information of the parent cells.
    b) are diploid, along with body cells and somatic cells.
    c) are haploid, while body cells and somatic cells are diploid.
    d) are involved in growth and repair of body cells.
    e) are produced only in terrestrial animals and plants.



25. The term ‘sclerophyll’ in a sclerophyll forest ecosystem is used to describe:
    Hint

    a) the leaves of the vegetation, which have a thick cuticle, helping them to keep their shape and preventing them from going limp.
    b) eucalyptus trees that usually occur in moderate to high rainfall areas.
    c) areas where the rainforests were destroyed by human intervention.
    d) the weather conditions that the dominant plant is subjected to in the area that it lives in.
    e) how high the trees that live in this area actually grow.



26. The arrival of the Europeans in Australia and the subsequent clearing of rainforest for agriculture and logging is thought to be responsible for changing the distribution of ecosystems. This is most likely to have resulted in:
    Hint

    a) the now contracted distribution of Australian rainforests.
    b) the change towards dry sclerophyll forests
    c) the current distribution of woodland ecosystems
    d) the present-day distribution of Australian ecosystems from rainforest to arid grassland systems.
    e) variation in the distribution shrublands.



27. What is one of the most easily observed features when comparing wet and dry sclerophyll ecosystems?
    Hint

    a) The presence of a ground cover of grasses and ferns
    b) The domination of eucalypt species
    c) The dry sclerophyll ecosystem usually has shorter trees with bent, twisted branches
    d) The wet sclerophyll ecosystem usually has an undergrowth of shrubs is present in the wet sclerophyll forest.
    e) An increased diversity of plants with reduced canopy



28. Abiotic factors that influence the distribution of Australian ecosystems include:
    Hint

    a) mean annual rainfall, water availability and temperature.
    b) shelter, soil type and topography.
    c) water availability, temperature and competition for resources
    d) soil type, predators and topography.
    e) mean annual rainfall, decomposers and temperature.



29. Agricultural development is seen as an issue for scientists because it may result in:
    Hint

    a) reduced biodiversity due to loss of species.
    b) improved access to global resources.
    c) reliance on too few crop species for food.
    d) the creation of seed banks.
    e) reduction in the variety of crops.



30. Scientists are currently studying the small tooth sawfish in north Western Australia, an endangered species in a number of areas in the world. Which of the following activities would be most helpful for the scientists studying the ecosystem when trying to determine the biodiversity of the ecosystem in which the fish lives?
    Hint

    a) Determining how hostile the environment is for the organisms consumed by the saw tooth fish
     b) Studying the abiotic components of the ecosystem only
     c) Developing an understanding of the effects of water temperature on survival
     d) Examining feeding relationships to develop an understanding of how healthy the ecosystem is
     e) Developing a quantitative understanding of pollution levels in the area





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