Chapter 4 Exam Style Questions

Chapter 4 – Exam style questions

Q1. Bk Ch4 Exam MQ1 Which of the following represent evidence that Australia was once part of the supercontinent of Gondwana? A geological evidence of more frequent volcanic activity in Australia in the past B similarities between present-day plants and animals on continents currently isolated from one another by the oceans C fossilised evidence of extinct Australian megafauna D changes in the Australian climate from colder to more temperate over the last 65 million years

A1. Bk Ch4 Exam MA1 B. The presence of similar organisms in different locations indicates common origins, with the population at some time being separated into different environments.

Q2. Bk Ch4 Exam MQ2 Geological evidence suggests that South America separated from the Australian–Antarctic landmass around 60 million years ago. Australia is believed to have broken away from Antarctica around 55 million years ago. What does the existence of the American opossum (a marsupial) suggests? A Marsupials evolved independently on different landmasses. B The opossum migrated to South America at some time after marsupial evolution was completed on the Australian continent. C The opossum was brought to the Americas by early nomadic humans. D Ancestral marsupials already existed more than 60 million years ago.

A2. Bk Ch4 Exam MA2 D. The presence of a marsupial in America when most marsupials are found only in Australasia suggests that they had a common ancestry but were separated as the continents drifted apart.

Q3. Bk Ch4 Exam MQ3 Australia has a large proportion of endemic species of plants and animals. What factors contribute to Australia’s richness of unique species? A its long isolation from other landmasses B early human activity such as selective breeding of favourable characteristics C travel to Australia by neighbouring islanders bringing plants and animals with them D change in climate from warmer to cooler over recent geological time

A3. Bk Ch4 Exam MA3 A. The Australian continent being isolated from other landforms meant it had a unique set of environmental conditions and consequent natural selection pressures.

Q4. Bk Ch4 Exam MQ4 Darwin proposed his theory of natural selection to account for the evolution of species on Earth. Which of the following statements does not represent a key point in this theory? A There is variation within every species. B Organisms in a population that have favourable characteristics have a greater chance of survival and reproduction compared with individuals without those characteristics. C Individuals that develop favourable variations of a particular characteristic are more likely to survive and reproduce compared with other individuals. D favourable characteristics gradually become more common in a population. Ch 4 Exam questions page 1 of 7

Copyright © Pearson Australia (a division of Pearson Australia Group Pty Ltd) A4. Bk Ch4 Exam MA4 C. Features developed during an organism’s lifetime (e.g. larger muscles) cannot be somehow translated into a gene, which can be passed on to the next generation.

Q5. Bk Ch4 Exam MQ5

Over the last 20 million years, the climate in Australia has become warmer and drier. This has resulted in which of the following changes? A an increase in the number of bushfires B an increase in the area covered by tropical rainforest C an increase in the area covered by grassland D a decrease in the area covered by woody sclerophyll forests

A5. Bk Ch4 Exam MA5

C. The drier, warmer climate has favoured grasslands rather than forests and woodlands, which need more water and higher temperatures.

Q6. Bk Ch4 Exam MQ6

The diversity of plant and animal species on earth is threatened most by which of the following activities? A the consumption of plants for food B the search for new medications C air and water pollution D destruction of natural environments

A6. Bk Ch4 Exam MA65

D. The destruction of natural environments clears plant species and removes food and shelter for animal species.

Q7. Bk Ch4 Exam MQ7

How many chromosomes will the body cells of an animal producing gametes with 16 chromosomes usually contain?

A 8 chromosomes B 16 chromosomes C 32 chromosomes D 64 chromosomes.

A7. Bk Ch4 Exam MA7 C. Gametes are diploid cells containing only half the number of chromosomes as the animal that produced them.

Q8. Bk Ch4 Exam MQ8 Which adaptation in animals increases the chance of successful fertilisation? Ch 4 Exam questions page 2 of 7

Copyright © Pearson Australia (a division of Pearson Australia Group Pty Ltd) A laying shelled eggs B direct transfer of male gametes into the female body C production of large numbers of eggs and sperm D internal development of the young

A8. Bk Ch4 Exam MA8 B. This action places the gametes into close proximity in a protected environment inside a female. A and D are post-fertilisation adaptations. C is an adaptation to counteract high infant mortality or a low fertilisation rate.

Q9. Bk Ch4 Exam MQ9 Why is the work of palaeobiologists in building a picture of the long-term changes that have occurred in Australian ecosystems important? A It contributes to our understanding of the evolution of endemic species of plants and animals. B It enables us to predict the impact of human activity in our present-day environment. C It helps us to plan appropriate management strategies to protect endangered species. D all of the above

A9. Bk Ch4 Exam MA9 D. Palaeobiologists examine fossils of plants and in doing so try to discover what flora has existed and deduce what the environment must have been like at the time. This can be extrapolated to predict how current trends can influence flora today.

Q10. Bk Ch4 Exam MQ10 The Tasmanian tiger or thylacine represents an example of the extinction of a species of Australian mammal. What is the most likely cause of the extinction of the thylacine? A the activity of early Australians in managing areas of land with fire B hunting since European settlement C competition with other species D the natural decline in global biodiversity.

A10. Bk Ch4 Exam MA10 B. Thylacines were hunted because they were regarded as killers of livestock. Eventually they were hunted to extinction.

Short Answer questions

Q1. Bk Ch4 Exam SQ1 Describe how the formation of mid-ocean ridges and spreading zones between continental plates provides evidence that supports the theory of continental drift.

A1. Bk Ch4 Exam SA1 Deep-sea surveys of mid-ocean ridges indicates that the further the rock making up the ocean floor is from the ridge, the older it is. The ocean floor appears to be spreading apart from the point where new ocean floor is created. Since the continents form a part of the crustal plates this evidence supports the theory that the continents are moving in continental drift.

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Copyright © Pearson Australia (a division of Pearson Australia Group Pty Ltd) Q2. Bk Ch4 Exam SQ2 a Explain how variation in a population is related to the chances of survival in a changing environment. b Suggest the likely consequence for a species that is unable to adapt to a changing environment. Explain.

A2. Bk Ch4 Exam SA2 a Populations that show variation in relation to some features are at an advantage in a changing environment. When environmental change occurs some individuals are likely to have characteristics that make them well suited to the new environment. Such individuals have a greater chance of survival and passing on those characteristics in reproduction. b Species that are unable to adapt to a changing environment have a reduced chance of survival, and extinction may occur. Individuals that do not have characteristics suited to the new environment have a reduced chance of survival to maturity and do not therefore pass on their characteristics to the next generation. When no members of a species have suitable characteristics the species may become extinct.

Q3. Bk Ch4 Exam SQ3 A quarry near Melbourne is the site of abundant fossil deposits of different kinds of seed-producing plants. Some resemble casuarinas that grow in tropical Australia; others are fossilised eucalypt leaves that are similar to bloodwood eucalypts that are now found only in far eastern Victoria and southern New South Wales. Palaeontological studies date the fossils at around 22 million years old. Describe the changes in environmental conditions in the area over the last 22 million years, as suggested by the evidence at this site.

A3. Bk Ch4 Exam SA3 The evidence suggests that 22 million years ago the area in question would have had a tropical climate, warmer and wetter than at the present time. These are the conditions required for the kinds of trees that were abundant at the time to flourish.

Q4. Bk Ch4 Exam SQ4

a Identify two reasons why the flower illustrated is likely to be wind pollinated. b Describe the mechanisms for pollination of a named Australian insect pollinated flower.

A4. Bk Ch4 Exam SA4 a Reasons can include exposed feathery stigmas presenting a large surface area, loosely hanging anthers to be easily shaken by the wind, small size, no brightly coloured flower parts. b Answer will depend on example chosen and may include colour, scent, nectar, sticky/heavy pollen, large size.

Q5. Bk Ch4 Exam SQ5 The continuation of species relies on successful reproduction between members of the species. Ch 4 Exam questions page 4 of 7

Copyright © Pearson Australia (a division of Pearson Australia Group Pty Ltd) a Name two events that must coincide in order that successful reproduction occurs within a species. b Describe two ways in which sexual reproduction increases variation within a species.

A5. Bk Ch4 Exam SA5 a Male and female members of a species must be ready to mate at the same time; male and female gametes must be brought together in fertilisation. b Sexual reproduction involves the process of meiosis in gamete production. Random segregation and crossing over are two events that increase variation within species. In random segregation, maternal and paternal chromosomes align independently during meiosis—this means that the gametes will have a mixture of genes of maternal and paternal origin. Crossing over occurs when duplicated homologous pairs lie side by side during the first stage of meiosis, touching and exchanging pieces of chromosome to form recombinant chromosomes—this further increases the amount of variation that can occur in the kinds of gametes that are produced.

Q6. Bk Ch4 Exam SQ6 The following map shows Australia as part of the supercontinent Gondwana, some 135 million years ago.

a Name the other modern-day landmasses that were part of Gondwana. b Describe two pieces of geological evidence that support the theory that the supercontinent of Gondwana existed. c Using Glossopteris (a kind of primitive seed fern) as an example, explain the biological evidence that supports this idea. d Describe the changes that have occurred in the Australian climate since its separation from Gondwana. e The Australian emu, African ostrich and South African rhea are examples of different but related flightless birds that inhabit different continents today. What conclusions can be drawn from this information in relation to the evolution of these different groups of birds?

A6. Bk Ch4 Exam SA6 a Australia, Antarctica, New Zealand, South America, Africa, Madagascar, India b Any two of: matching rock strata on the different continents; contours of the continents resemble the pieces of a jigsaw that appear to fit together; deep-sea surveys of mid-ocean ridges between

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Copyright © Pearson Australia (a division of Pearson Australia Group Pty Ltd) tectonic plates indicate that the further the rock forming the ocean floor is from the ridge, the older it is. c Fossils of Glossopteris have been found in rocks of the same age on different continents believed to have been part of Gondwana, for example in Australia, New Zealand, Antarctica, India, South America and Africa. d Australia’s climate has changed since its separation from Gondwana. It became a separate continent after a final split from Antarctica about 45 million years ago and has continued to move northwards since then. With this movement towards the equator the temperature has increased, changing the climate from cool and wet to warm and dry. e These flightless birds represent species that are related to one another. If this is the case they must share a common ancestral form. This suggests that the landmasses on which they are currently found must have been joined at some time in the past.

Q7. Bk Ch4 Exam SQ7 Study the evolutionary tree representing examples of extinct and present-day Australian fauna.

diprotodon (large wombat-like marsupial; extinct)

ancestral species northern hairy-nosed wombat (Lasiorhinus krefftii)

southern hairy-nosed wombat (Lasiorhinus latifrons) a Use Darwin’s theory of natural selection to account for the evolution of the two different species of wombat represented in the diagram. Include a discussion of • natural variation • different environmental pressures • adaptations to different environments • subsequent generations. b Outline two reasons that account for the disappearance of Australia’s megafauna.

A7. Bk Ch4 Exam SA7 a The northern hairy-nosed wombat and the southern hairy-nosed wombat shared a common ancestor. Variation existed within the population of that ancestral group. Movement of different populations saw them inhabit different localities with different environmental pressures. Populations in different areas would have become geographically and therefore reproductively isolated from one another over a long period of time. Different environmental pressures would have favoured different forms of the same characteristic in the two groups. Individuals within each group that had the characteristics most suited to their particular environments would have had the best chance of reaching reproductive age and passing on their characteristics to their offspring, while those individuals without the most favourable characteristics would have died out. In this way the most favourable characteristics in each group became more common and subsequent generations become more and more adapted to their particular environments. Over time the two populations become so different from one another that they no longer reproduced in nature and the two are said to be different species. b Climate change is one factor believed to have contributed to the extinction of Australia’s megafauna—after the last Ice Age environmental conditions became warmer and drier, changing the nature of the ecosystems to which the megafauna were adapted; the arrival of humans also impacted on the megafauna, with hunting believed to have been another factor contributing to their decline.

Q8. Bk Ch4 Exam SQ8

The diagram shows a cell containing two pairs of chromosomes just before meiosis. Ch 4 Exam questions page 6 of 7

a Draw the daughter cells produced after meiosis has occurred. b State two differences between the cells you have drawn and the cells produced after mitosis c Explain how sexual reproduction results in variation in the offspring.

A8. Bk Ch4 Exam SA8

4 cells should be shown each containing one long and one short chromosome a Only 2 cells are produced after mitosis, 4 are produced after meiosis. The cells produced after mitosis contain the full set of chromosomes, after meiosis each cell contains half the number of chromosomes. b Sexual reproduction results in variation in the offspring as they receive half their chromosomes from one parent and half from the other parent. This results in a new combination of genes.

Q9. Bk Ch4 Exam SQ9

Ascidians (sea squirts) are animals commonly found attached to rocks at low tide. Some species can reproduce both sexually and asexually. Through asexual reproduction large colonies become established on certain rocks. a Identify one advantage of asexual reproduction for seasquirts. b Many Australian plants are capable of reproducing both sexually and asexually. Identify one example of such a plant and describe one condition under which asexual reproduction occurs. c For the seasquirt and also your named plant, explain the advantage of also being able to reproduce sexually.

A9. Bk Ch4 Exam SA9 a The advantage to seasquirts is that it allows a favourable environment to be rapidly colonized. b Plant example used must be Australian and named. Condition will depend on example chosen. c The advantage of being able to reproduce sexually is that sexual reproduction results invariation. In a changing environment there is an increased chance that the species will survive if variation exists.

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