Unit 1 Biodiversity and the interconnectedness of lifemissrayneryr11biology.weebly.com/uploads/5/6/6/0/...a deforestation, which has decreased the nutrient run-off into the oceans

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Unit 1 Biodiversity and the interconnectedness of life

Unit exam

Time permitted: 70 minutes

Section Number of questions Marks availableA Multiple choice 30 30B Short answer 9 50

Total 39 80

Grade:

Comments:

Section a multiple choice (30 marks)Section A consists of 30 questions, each worth one mark. Each question has only one correct answer. Circle the correct answer. Attempt all questions. Marks will not be deducted for incorrect answers. You are advised to spend no more than 30 minutes on this section.1 Biodiversity can be described as:

a the variety within and between all species of plants, animals and microorganisms.

B the variety between members of a particular species.

C the variation found within a biome.

D the variation in number of species within a particular area.

2 Javan rhinos used to be the most widespread Asian rhinoceroses but the few left in the wild now live in two small national parks. The fact that this species lives nowhere else is an example of:

a a unique species.

B an introduced species.

C a phylogenetic species.

D an endemic species.

3 According to the biological species concept, a species consists of:

a individuals that can and do interbreed and are reproductively isolated.

B individuals that form the smallest cluster within a particular environment.

C individuals which are capable of breeding if they are put together artificially.

D individuals that have the same DNA and therefore behave alike.

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4 The current system of naming a species uses which of the following two levels of classification?

a Phylum and class

B Order and class

C Genus and family

D Genus and species

5 A popular system used by scientists is to classify organisms into five kingdoms. This is based on the nature of the organism’s:

a nutrition.

B cells.

C reproduction.

D environment.

6 The kingdom of the eukaryotes not classified as plants, animals or fungi is known as:

a fungi.

B protista.

C plantae.

D archaeae.

7 A multicellular, autotrophic, eukaryotic organism would be classified as:

a a protist.

B a plant.

C a fungus.

D a bacterium.

8 Evolutionary relationships among a group of organisms can be displayed using a:

a dichotomous key.

B binomial name.

C cladogram.

D molecular clock.

9 Which of the following lists the correct classification levels, from largest group to smallest?

a Phylum, order, class, genus, family

B Order, phylum, class, family, genus

C Phylum, class, order, family, genus

D Class, phylum, order, family, genus

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10 Scientists use a dichotomous key to:

a locate an organism and its niche.

B divide a kingdom into smaller groups.

C identify an organism.

D ‘unlock’ the relationships between two organisms

11 The common housefly belongs to all of the following levels of classification. If you had access to textbooks, which of the following levels would give you the most specific information about this species?

a Order Diptera

B Genus Musca

C Class Hexapoda

D Family Muscidae

12 Abiotic factors influence the ability of an organism to survive in a particular environment. An example of an abiotic factor is:

a the number of predators present during the day.

B the number of predators present during the night.

C the annual amount of rainfall.

D the total number of animals living in the environment.

13 A species of freshwater fish is known to require cold water, low oxygen content, water that is shallow and clear, with a sandy substrate on the bottom. These requirements are part of the fish’s:

a primary habitat.

B home base.

C zone of intolerance.

D tolerance range.

14 The structure and organisation of ecosystems are affected by which of the following biotic factors?

a Nutrient availability, soil pH, temperature

B Predation, competition, disease

C Light intensity, rainfall, wind

D Temperature, predation, amount of fresh water

15 In the ocean around Tasmania, large kelp forests exist. Which of the following would most likely be the keystone species in these marine ecosystems?

a Kelp

B Sea urchins which feed on the kelp

C Fish which feed on the kelp

D Dugongs which feed on the kelp

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16 Orchids naturally live on the limbs of trees, which does not affect the trees. The orchid is better able to access light. This is an example of:

a parasitism.

B commensalism.

C mutualism.

D resource partitioning.

17 In a parasitic relationship between two organisms:

a both species benefit.

B one species benefits, the other species is not affected.

C one species benefits, the other species is weakened.

D neither species benefits.

18 Which of the following is not a biome?

a Savannah grassland

B Desert

C Tundra

D Estuary

19 Grazing animals such as samba deer are considered to be:

a producers.

B primary consumers.

C secondary consumers.

D autotrophs.

20 Animals such as whales which feed on zooplankton are considered to be:

a producers.

B primary consumers.

C secondary consumers.

D autotrophs.

21 In a natural ecosystem, which of the following pyramids can never be inverted?

a Pyramid of numbers

B Pyramid of biomass

C Pyramid of energy

D None of the above: all pyramids can be inverted in certain conditions

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22 Which of the following organisms would be classified as a detritivore?

a A mouse

B An owl

C A flowering gum tree

D A bacterium

23 In a natural ecosystem, the biomass is the total amount of matter at a particular time. The biomass of herbivores would be expected to be _____________ the biomass of carnivores.

a greater than

B the same as

C less than

D not affected by

24 Which of the following contains a large amount of carbon and can therefore be considered to be a carbon sink?

a The oceans

B The atmosphere

C The soil

D Peat

25 Which of the following is true for r-selected species?

a They give little or no parental care.

B They have large eggs or offspring.

C They have a longer lifespan.

D There are few offspring in each reproductive cycle.

26 An ecologist is interested in measuring the abundance of wombats in a forest in eastern Victoria. Which method is she most likely to use?

a Random quadrats

B A series of transects

C Capture–mark–recapture

D Radio tracking

27 Which of the following is not a density-dependent factor which can limit animal populations?

a Weather conditions

B Competition for food

C Mortality rates

D Predation

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28 Organisms can recolonise an area via secondary succession. Secondary succession:

a occurs after a fire or flood.

B occurs after a volcanic eruption.

C always occurs after primary succession.

D usually begins with lichen colonising a rock face.

29 Biological control agents exploit relationships between organisms. An example of a biological control against an insect pest is the use of:

a herbicides.

B pesticides.

C an insect pheromone (sex hormone).

D lights which attract the insects at night, then kill them with an electric current.

30 Worldwide, the number of fish available for fishing has decreased due to:

a deforestation, which has decreased the nutrient run-off into the oceans.

B overexploitation.

C extinction, as they are no longer well adapted to their environment.

D secondary succession.

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Section B Short answer (50 marks)Section B consists of 9 questions. Write your answers in the spaces provided. You are advised to spend 40 minutes on this section.1 The barn owl (Tyto alba) lives in rural habitats in Britain, commonly in farm buildings that are not

disturbed by humans. The barn owl is a top carnivore which feeds at night on small rodents. Recently, barn owl populations have declined. Give TWO possible reasons which may explain this decline. (2 marks)Answer: Reasons could include:• fewernestingsitesasoldfarmbuildingsareknockeddown

• fewerpreyanimals(rodents)duetopesticideuse

• fewerpreyanimalsduetolossofhabitatfortheprey

• greaternumberdyingduetopesticideswhichhaveaccumulatedthroughthefoodchain

• increaseinroadtraffic.Theowlsareshyandwouldbedisturbedbythenoise

2 Using an example, explain the competitive exclusion principle. (2 marks)Answer: The competitive exclusion principle states that two or more species competing for the same resource cannot coexist in the same community. For example, two species of tree creeper that are canopy feeders would not be found in the same tree.

3 a Mary counted 700 aphids on one of her bean plants. She also found five ladybirds that were feeding on the aphids. Create a food chain for this community. (1 mark)Answer: Bean plant → aphid → ladybird

b Some energy is lost at each stage of a food chain such as the one in Mary’s garden. Explain TWO ways that energy can be lost from a food chain. (2 marks)Answer: Any of the following:• heatloss

• physicalmovement

• excretion/productionofwaste(urine/faeces)

c Create a pyramid of biomass for Mary’s community. Label the pyramid. (2 marks)Answer: Triangular pyramid with three layers, as blocks or as a triangle. Layer should be appropriately labelled: bean plant, aphid, ladybird.

4 a Draw a food web for the ecosystem described below.In a particular aquatic ecosystem, tadpoles, water beetles and snails feed on freshwater algae. Frogs eat both the water beetles and the snails, and they are in turn preyed upon by kingfishers. Small fish that live in the stream feed on tadpoles. The small fish are sometimes taken by the kingfishers. (4 marks)Answer: King�sher

Small �sh Frog

Algae

SnailWater beetleTadpole

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b Name the autotroph(s) in your food web. (1 mark)Answer: Algae

c What group of organisms has not been included in your food web? (1 mark)Answer: Decomposers

d What role do these organisms play in an ecosystem? (1 mark)Answer: Break down dead organisms, which recycles the inorganic nutrients from their bodies.

e Why can a eucalypt forest be described as an ecosystem? (1 mark)Answer: A eucalypt forest is a community of organisms occupying a particular region where there is an interaction between living and non-living components.

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Begin EndLINE TRANSECT

1 2 3 4 5 6 7 8 9 10

a The transect method of sampling (above) is used by ecologists to systematically collect data about a particular community. What type of data about the biotic features is often collected using this method? (1 mark)Answer: Transects are used to determine the distribution of species within a community.

b What type of data about the abiotic features of an ecosystem is often found using this sampling method? Provide two examples. (2 marks) Answer: Abiotic features that can be measured using transects include soil type, pH and salinity.

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2 ppm

Bird

Fish

Plankton

Water

1600 ppm

200 ppm

5 ppm

a What biological process is illustrated in the diagram above? (1 mark)Answer: Biological magnification

b Provide an example of a substance that demonstrates this process. (1 mark)Answer: Examples include DDT, mercury, arsenic and pesticides.

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c Explain why this process occurs. (1 mark)Answer: The substances cannot be broken down by the body. Instead they are stored in the animal’s tissues. They accumulate over the lifetime of the animal and remain in its tissues until the animal dies.

In the 1950s, the World Health Organization sprayed DDT in Borneo as a way of controlling mosquitoes which carry malaria. The DDT killed the mosquitoes, but also killed a species of wasp which normally eats caterpillars. The caterpillar is a problem as it feeds on the thatched roofs of houses.

d Suggest what outcomes may have happened over time with the wasp numbers reduced. (1 mark)Answer: With wasp numbers reduced, caterpillar numbers would have increased, and there would be more damage to the thatched roofs.

e Gecko lizards ate the poisoned mosquitoes and wasps. They did not die, but village cats which ate the geckos did die. Suggest one effect of reducing cat numbers in the villages. (1 mark)Answer: With cat numbers reduced, there would be less predation on the village rats. Rat numbers would increase as a result.

7 European rabbits (Oryctolagus cuniculus) were introduced by settlers into Australia in 1859, when 24 rabbits were released near Geelong. Very quickly, the rabbit population grew enormously across the continent. The rabbit’s rapid spread led to the destruction of large areas of vegetation and the extinction of many plant species. Farmers attempted to control the rabbits by shooting, using poisons, destroying warrens and eventually introducing the Myxomatosis virus (in 1950), as a form of biological control. This virus, a natural parasite of the Brazilian forest rabbit, was lethal for European rabbits. It quickly reduced Australia’s rabbits to a mere 5% of former numbers. However, this solution was not long-lasting and rabbit numbers recovered.

a Name and describe a procedure for estimating rabbit numbers in a particular area. (4 marks)Answer: Capture–mark–recapture method: answer should explain how rabbits were captured, how they were marked, the recapture and count.

b Suggest why rabbit numbers increased rapidly in the first 70 years. (1 mark)Answer: No predator to control them, OR plenty of food with no competitors

c Suggest why rabbits were introduced into Australia by settlers. (1 mark)Answer: Any of:• thesettlerswereaccustomedtohavingrabbitsintheirfields

• thesettlerswereaccustomedtohuntingrabbitandwantedtodothatinAustralia

• thesettlerswereaccustomedtoeatingrabbit.

d Describe two possible effects on an ecosystem when a plant species dies out. (2 marks)Answer: Extinction of a plant species could:• increasesoilerosion

• decreasethenutrientsavailabletootherspecies

• causeadecreaseinconsumernumbers

• increasethenumberofacompetingplantspecies.

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e Suggest one advantage and one disadvantage of biological control as a means of controlling pest populations. (2 marks)Answer: An advantage of biological control is that no harmful chemicals are being used.Disadvantages of biological control include:• theintroducedspeciesmaynotbespecifictothepestspecies

• animmunitycandevelopinthepestspecies.

f Suggest why rabbit numbers eventually recovered after the introduction of the Myxomatosis virus. (1 mark)Answer: The rabbits developed an immunity to the virus.

8 a Energy is required by organisms to carry out work. This includes keeping warm and growing. Give TWO other uses of energy by organisms. (2 marks)Answer: Other uses of energy include: repair, production of gametes, movement, digestion, synthesis of proteins such as enzymes.

b Nitrogen is an essential element for living things, including plants. Nitrates in the soil are taken up by plants and used. What is the main organic compound that is made with the nitrates? (1 mark)Answer: Proteins

c Gaseous nitrogen makes up about 80% of the atmosphere. It can be removed and ‘fixed’ , which means it enters the nitrogen cycle. Give TWO ways that nitrogen can be removed from the atmosphere. (2 marks)Answer: Nitrogen can be fixed by:• nitrogen-fixingbacteria,whichlivesymbioticallyinnodulesonlegumessuchasclover

• prokaryotes,whichlivefreelyinthesoilandabsorbnitrogengasfromairspacesinthesoil

• lightning,whichformsoxidesofnitrogen

d Phosphorous is another essential element for living things. What are TWO ways that both plants and animals use phosphorous? (2 marks)Answer: Phosphorous is used in plants and animals for the production of ATP and DNA.

9 a 110 million years ago, Australia was part of a supercontinent. Name that supercontinent. (1 mark)Answer: Pangaea

b The supercontinent started to break up into two large land masses, one to the north and one to the south. Give the names of these two land masses. (2 marks)Answer: Northern landmass: Laurasia, southern landmass: Gondwana

c The two landmasses broke up and became the countries we know today. Name the process by which landmasses move over time. (1 mark)Answer: Continental drift

d Australian organisms have been affected by the movement of the Australian continent. Describe one effect on Australian species. (1 mark)Answer: Australia has a high number of endemic species, as a result of being isolated from other continents for a long time.

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e Large numbers of organisms have at times disappeared across the world in what is known as mass extinction events. Name one of the possible causes for mass extinctions that is relevant to Australia. (1 mark)Answer: Causes of mass extinctions relevant to Australia include:• climatechange

• variationsinsealevel

• variationsinatmosphericoxygen

• impactofasteroids.

f What information about the history of Earth can be obtained from ice cores? (1 mark)Answer: Ice cores are a continuous record of past climatic conditions. They tell us when there have been ice ages and how sea levels have varied.

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Unit 1 Biodiversity and the interconnectedness of lifemissrayneryr11biology.weebly.com/uploads/5/6/6/0/...a deforestation, which has decreased the nutrient run-off into the oceans