biology 2014 year 11 te unit 2 - quia

VCE BIOLOGY 2014

YEAR 11 TRIAL EXAM

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Unit 2 Time allowed: 90 minutes

Total marks: 75

25 Multiple Choice Questions 9 Short Answer Questions

An Answer Sheet is provided for Section A

Answer all questions in Section B in the space provided

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Learning Materials by Lisachem VCE Biology 2014 Year 11 Trial Exam Unit 2

Student Name....….……………………................................................................ VCE Biology 2014 Year 11 Trial Exam Unit 2 There are 25 Multiple Choice Questions to be answered by circling the correct letter in the table below. Use only a 2B pencil. If you make a mistake, erase it and enter the correct answer. Marks will not be deducted for incorrect answers.

Question 1 A B C D Question 2 A B C D












Question 25 A B C D

STUDENT NUMBER Letter

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Learning Materials by Lisachem VCE Biology 2014 Year 11 Trial Exam Unit 2 1

VCE Biology 2014 Year 11 Trial Exam Unit 2

SECTION A – Multiple Choice Questions Question 1 A biotic factor which could influence the success of a species of plant in a particular geographic location might be the A. soil pH levels. B. availability of minerals and soil nutrients. C. presence of pollinating insect species. D. amount of natural light available. Question 2 A structural adaptation which promotes increased heat loss, and which is used by some heat tolerant animals to aid their survival in desert regions, would be A. the ability to constrict their surface blood capillaries during the hottest part of the day. B. the presence of large ears near the head region of the animal. C. the ability to minimise the rate of perspiration when water availability is limited. D. the presence of a layer of hair over all their exposed external surfaces. Question 3 The dromedary camel (Camelus dromedarius) is well known for its ability to survive harsh desert conditions. Amongst a number of different adaptive strategies, the camel's kidneys play a major role in the process of conserving water. The camel's kidneys do this by having a strong capacity for water reabsorption and the ability to produce and eliminate very concentrated urine. These two features in the kidneys of dromedary camels are best described as being A. structural adaptations. B. behavioural adaptations. C. physiological adaptations. D. biochemical adaptations. Question 4 The western blue-tongued lizard is a large skink native to Australia. Being diurnal, it hunts for insects, spiders and snails during the day and rests under leaf litter or rocks at night. As the western blue-tongued lizard behaviourally regulates its body temperature during the day time, it would be accurate to classify this animal as a A. homeothermic endotherm. B. poikilothermic ectotherm. C. homeothermic ectotherm. D. poikilothermic endotherm.


Question 5 With respect to the function and structure of nerve cells, it would be true to say that A. dendrites are only present in effector and connector neurones. B. effector neurones directly receive impulses from the peripheral nervous system along

polysynaptic pathways. C. nerve impulses have a long lasting effect and are non-specific with regard to their

target tissues. D. connecting neurones can carry impulses away from the central nervous system to

sense organs via afferent neurones. Question 6 In mammals, hormones are A. usually peptides or steroids produced by one tissue and conveyed by the blood stream

to another to affect physiological activity. B. fast acting compounds resulting in increased growth or metabolism in the tissues in

which they are produced. C. large biomolecules which work independently of the nervous system. D. active in large amounts, typically target specific and transported via the lymphatic

system. Question 7 Which of the following features listed below would not assist an amphibian to osmoregulate in a fresh water environment? The ability to A. produce large quantities of dilute urine containing urea and ammonia when in water. B. actively transport sodium and chloride ions across the skin from the surrounding water

into the body to balance diffusion loss from the body. C. produce concentrated urine when in dry air. D. lose salts continually across their permeable skin by diffusion to the external

environment.


Question 8 Figure 1 shows how a climbing rose plant grows with the support of a garden stake.

Figure 1 Based on the information in Figure 1, the growing rose plant would probably A. produce cytokinins in response to the presence of the stake. B. stop responding to all stimuli at night. C. respond to gravity, touch of the stake and availability of light. D. display thigmotropism during daylight hours only. Question 9 The American behaviourist, Edward Thorndike, proposed a theory that learning occurred through a process of trial and error. He tested this theory by conducting an experiment which involved the use of the equipment shown in Figure 2 below.

Figure 2 In Thorndike's experiment, hungry cats were individually placed into a box that could be opened by the animal via a device such as a latch. Once outside of the box, the cats gained access to food. It was observed that the more trials of training the cats had been given, the less time it took for the cats to get out of the box. The observations made in this study indicate an example of A. operant conditioning. B. habituation. C. classical conditioning. D. insight learning.


Question 10 Which of the following features or mechanisms found in Australian flora would not enhance the chances of cross pollination by insects, birds or mammals? A. The presence of nectar, pollen or scented flowers. B. The ability of some plants to mimic the appearance or pheromone smell of insects. C. The presence of thick woody seed pods which only drop seeds following a bush fire. D. The ability to flower at different times in the year, other than spring. Question 11 An organism's trophic level, the humidity and temperature an organism prefers and when the organism reproduces, are all features which would be included in a description of an organism's A. habitat. B. ecosystem. C. niche. D. community. Question 12 Radiotelemetry, very high frequency (VHF) radio tracking and satellite tracking are all examples of current technological monitoring techniques which can be used to A. identify the positions of animals as they move within their habitats in search of food or

a mate. B. determine the distribution of certain plant and animal species over a large scale area. C. measure plant growth and change in inaccessible regions. D. differentiate between soil and vegetation as well as deciduous and evergreen trees in

remote areas. Question 13 Decomposers play an important role in ecosystems because they A. are able to capture sunlight and convert this trapped light energy into organic

compounds through the process of photosynthesis. B. can biochemically synthesise complex compounds from simple ones. C. occur at the highest levels of energy pyramids. D. have the ability to break down organic matter thus making important nutrients

available for producers to re-use. Question 14 An ecological pyramid which records the total dry organic matter of organisms at each trophic level in a given area of an ecosystem A. illustrates how energy flows through a food web. B. shows the number of organisms at each trophic level. C. can be inverted if the biomass is sampled over a short period of time. D. is important because it indicates the number of species at each trophic level. Question 15 The logistic model of population growth shows A. an increasing rate of population growth which continues indefinitely. B. a decrease in death rate as the population grows. C. that environmental changes have no impact on the carrying capacity of the habitat. D. that the birth rate decreases as the population nears its carrying capacity.


Question 16 A community becoming established in an area that has not been colonised by any other species previously is an example of A. primary succession. B. secondary succession. C. climax acclimation. D. bioaccumulation. Question 17 Species that utilize the same source of nutrition within a food web can best be described as A. restricting the energy flow in the cycle. B. occupying the same trophic level. C. being tertiary consumers. D. being omnivorous organisms. Question 18 Biocontrol measures are often used to restrict the spread of exotic pests and weeds in preference to the use of chemicals because they are A. less expensive, as only small amounts need to be used. B. typically species specific and will not kill other beneficial organisms in the area. C. easier to apply over larger areas. D. more readily available. Question 19 In the nitrogen cycle, the inter-relationship which exists between the nitrogen-fixing bacteria and the leguminous plants in whose roots they live, is best described as an example of A. parasitism. B. mutualism. C. commensalism. D. competition. Question 20 Two processes by which carbon dioxide is released back into the atmosphere during the carbon cycle would be A. cellular respiration and combustion. B. photosynthesis and transpiration. C. ammonification and cellular respiration. D. cellular respiration and photosynthesis. Question 21 All the red deer living in a particular forested area would be an example of a A. community. B. population. C. biosphere. D. niche.


Question 22 Figure 3 shows a food chain present in a marine environment.

Figure 3 In the marine food chain shown in Figure 3, the organism most likely to use photosynthesis to convert inorganic carbon into protoplasm would be A. zooplankton. B. filter feeders. C. phytoplankton. D. predatory fish. Question 23 Remora fish, sometimes called "suckerfish, are a family (Echeneidae) of ray-finned fish in the order Perciformes. Remora fish are often found in close association with other marine organisms such as sharks, manta rays, whales, turtles, and dugongs. In these relationships the remora fish eat their host's parasites, along with other debris, helping to maintain the host's health. The remora fish in return receive food and protection. In these situations, the interspecific interaction between the remora fish and the other marine organisms they associate with is best described as being an example of A. ammensalism. B. mutualism. C. commensalism. D. parasitism. Question 24 It would be true to say that, in terms of ecological pyramids, in a deep water ecosystem a A. pyramid of numbers would always be upright. B. pyramid of biomass would always be upright. C. total energy flow at successive trophic levels would increase. D. pyramid of energy would never be inverted. Question 25 Both energy and matter flow through the biosphere. However, the flow of matter differs from the flow of energy in that A. matter flows in cycles whilst energy only flows in one direction. B. the amount of matter produced at each trophic level diminishes whilst energy levels at

each trophic level rises. C. matter enters the biosphere as organic material whilst energy flow enters as inorganic

material. D. matter flows from consumers to producers whilst energy flows from producers to

consumers.

End of Section A



SECTION B – Short Answer Questions Question 1 (5 marks) The koala (Phascolarctos cinereus) is an arboreal, herbivorous marsupial native to Australia. In terms of physical characteristics, koalas possess two opposable digits on their forepaws, tough textured skin on the soles of their feet, long sharp claws, strong thigh muscles and extra thick fur on their bottoms. They also have two fewer pairs of ribs than most mammals and a curved backbone. Koalas are territorial animals that generally live separately in their own home ranges. They define their territories by making scratch marks on trees. Males also secrete a sticky brown substance from a scent gland in their chest that they rub on the bark. Mating season, which occurs between the months of August to February, is the only time koalas seek one another out and come together. Breeding time is a time of increased activity, and sound levels increase as males bellow more frequently. This is also the time when the young from the previous year are dispersing from their mothers in order to find a territory of their own. a. Identify a structural adaptation of koalas that both assists their tree dwelling lifestyle,

as well as providing a means by which they can communicate with other koalas to minimise competition for resources. 1 mark

______________________________________________ Koalas inhabit the forests of eastern Australia, with different subspecies in the northern and southern regions. Table 1 below compares and contrasts some features between the two subspecies considered. Feature Southern subspecies Northern subspecies

Body length (cm) 60-85 60-85 Body mass (kg) 7-13 4-8.5 Thickness and length of fur thick and long thin and short Length of fur long short

Table 1 b. What two features would aid the survival of the southern subspecies of koala during

the winter months and explain fully how this is achieved? 2 marks

Feature 1:

______________________________________________ Survival advantage in winter months:

______________________________________________ ______________________________________________ ______________________________________________


Feature 2:

______________________________________________ Survival advantage in winter months:

______________________________________________ ______________________________________________ ______________________________________________ Koalas are very select eaters. They are capable of feeding on and deriving nourishment from eucalyptus leaves, which are highly fibrous and poisonous to most other animals. They are able to do this because they possess bacteria in their stomach which break down the fibre and toxic oils in eucalyptus leaves and which help them absorb 25% of the nutrients present in the leaves. Their direct water intake is generally quite low. Koalas tend to get all the moisture they need from eucalyptus leaves. c. What behavioural adaptation might koalas employ to overcome the energy deficit

which results from their low calorific diet? 1 mark

______________________________________________ ______________________________________________ ______________________________________________ d. Given koalas lack sweat glands, how would these animals cool themselves during the

hotter months of the year? 1 mark

______________________________________________ ______________________________________________ ______________________________________________


Question 2 (9 marks) Figure 4 shows a typical food web encountered in Antarctic regions.

Figure 4 a. Identify a predator-prey food chain which contains at least five organisms from the

food web shown in Figure 4. 1 mark

______________________________________________ ______________________________________________ b. For the predator-prey food chain given in 1a identify the following organisms: 2 marks

i. producer _____________________ ii. third order consumer _____________________ iii. herbivore _____________________ iv. top order consumer _____________________


An estimation of the biomass of the five populations listed in the predator-prey food chain given in 1a was made. Table 2 summarises these estimates. A-E represents the populations of the five different species considered.

Population Biomass estimate (kg) A 485 B 6 C 51,000 D 55 E 4,950

Table 2 c. Based on the information provided in Table 2 and using the predator- prey food chain

nominated in 2a, draw a pyramid of biomass. In this pyramid of biomass, ensure populations A-E are clearly identified as the relevant organisms in the predator-prey food chain considered. 2 marks

A marine biologist, based on a research unit in Antarctica, decided to study the population dynamics of some of the marine organisms in the area. Initially he focussed on the relationships between the krill, phytoplankton and baleen whale populations. d. Describe the feeding relationship between the three populations of organisms being

studied by the marine biologist. 1 mark

______________________________________________ ______________________________________________ ______________________________________________ e. If a new predator moved into Antarctic waters and also fed on krill, what would

happen to the numbers of the three populations in the feeding relationship considered in 2d? 3 marks

______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________


Question 3 (8 marks) Phosphorus is an essential nutrient to all forms of life. a. Name one important biological molecule that phosphorus is part of and describe the

role the molecule identified plays in the overall survival of living organisms.

Biomolecule: ______________________________________ 1 mark Role it plays in organism's survival: 1 mark

______________________________________________ ______________________________________________ ______________________________________________ Figure 5 shows the major processes by which phosphorus recycles through an ecosystem.

Figure 5: The Phosphorus cycle b. How does the movement of phosphorus through an ecosystem differ from the

movement of i. energy through an ecosystem? 1 mark

______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________


ii. carbon and nitrogen through an ecosystem? 1 mark

______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________ c. Name one natural, abiotic source of insoluble phosphate which occurs in an

ecosystem. 1 mark

______________________________________________ d. How is this form of phosphorus made available to living organisms in an ecosystem? 1 mark

______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________ e. In unpolluted areas, what can be said about the rate at which phosphorus would enter

ecosystems? 1 mark

______________________________________________ In many agricultural areas, superphosphates are applied by farmers to replace phosphorus lost from the soil by leaching. In urban settings washing detergents containing phosphates overflow from sewerage systems and animal droppings would also contribute to raising levels of phosphorus in the environment. f. What would be the consequence of elevated levels of phosphorus in natural water

systems as a result of human activities to marine life? 1 mark

______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________


Question 4 (3 marks) Interspecific interactions are interactions among organisms of different species. All species involved in the interaction may experience positive, neutral, or negative benefits. Table 3 below summarises the different outcomes for two organisms in an interspecific relationship. Effect on organism 2 Harm Benefit No effect Effect on organism 1

Harm a) b) Benefit c) d) e) No effect f)

Table 3 Based on your knowledge of interspecific relationships, complete Table 3 by inserting the appropriate biological term. 3 marks Question 5 (8 marks) The island of Madagascar, off the east coast of Africa, is the only known habitat of the Madagascar rosy periwinkle (Catharanthus roseus). a. Distinguish clearly between the terms habitat and niche. 2 marks

______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________ b. In ecology, what term is used to describe an organism like Catharanthus roseus whose

distribution is restricted to a specific geographic location? 1 mark

______________________________________________


Catharanthus roseus, a herbaceous plant, typically grows to one metre in height and possesses oval shaped, broad and thin, glossy green, hairless leaves. It is characterised by white to dark pink flowers with dark red centres. c. Given the leaf description of Catharanthus roseus, what type of environment would

you expect such a species of plant to thrive in? Justify your answer by relating it to the leaf structure of Catharanthus roseus. 2 marks

Environment:

______________________________________________

Leaf structure adaptation:

______________________________________________ ______________________________________________ ______________________________________________ In the wild, Catharanthus roseus, is an endangered plant. This is largely due to the human practice of "slash and burn" agriculture. d. Why would such an agricultural practice impact negatively on the distribution of

Catharanthus roseus? 1 mark

______________________________________________ ______________________________________________ ______________________________________________ As well as the detrimental effects of land clearing by human agricultural practices, the distribution of Catharanthus roseus has also been severely impacted by overharvesting. Catharanthus roseus is the only known plant to produce vincristine and vinblastine, two chemicals used to combat Hodgkin's disease, a leukaemia like disease that affects thousands of people each year. e. Other than its medicinal benefits, give another reason why it is important to prevent

human caused extinction of wild populations of species like Catharanthus roseus. 1 mark

______________________________________________ ______________________________________________ ______________________________________________ f. Aside from land clearing and overharvesting, give another example where human

activities have resulted in changes to an abiotic factor within an ecosystem, leading to potentially negative effects on life in the area. 1 mark


Question 6 (5 marks) A population of microscopic bacteria growing in a large flask had the growth pattern shown in Figure 6.

Figure 6 a. What pattern of population growth is being shown in Figure 6? 1 mark

______________________________________________ b. Describe a biological factor that determines the shape of the growth pattern of the

bacterial population shown in Figure 6 during period 2. 1 mark

______________________________________________ ______________________________________________ ______________________________________________ c. Where on the population graph shown in Figure 6 does maximum growth rate of the

bacterial population occur? Justify your answer. 1 mark

______________________________________________ d. For this bacterial population, what is its carrying capacity and when is it reached? 1 mark

______________________________________________ ______________________________________________ e. If the size of a shark population, which is a K-selected strategist, dropped suddenly in

an area as a result of excessive culling, would the shark population in that area be at risk of extinction? Justify your answer. 1 mark

______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________


Question 7 (4 marks) Transpiration is the process by which plants lose water from their above ground surfaces. This water loss occurs predominantly through the stomata, small openings on the leaf surface, with some water loss occurring through the cuticle. Up to 98% of water absorbed by a plant can be lost via transpiration with only 2-5% retained by the plant. Environmental factors like air temperature, humidity and air movement can influence the rate of water loss from a plant. Table 4 shows the average transpiration rate in a group of seedlings, when exposed to different temperatures.

Temperature (°C) 18 22 26 29

Transpiration rate(mmol/m2sec) 1.5 3 5 4.5

Table 4 Based on the data provided in Table 4, it can be concluded that, for temperatures between 18 - 26° C, the trend observed is that as temperature increases so does the rate of transpiration. a. Account for the difference in transpiration rate between 26-29°C? 1 mark

______________________________________________ ______________________________________________ ______________________________________________ b. What would be the effect on the transpiration rate of a plant if the humidity increased

at a constant temperature? 1 mark

______________________________________________ ______________________________________________ ______________________________________________ c. Name a structural feature that can help reduce water loss in a plant and explain how it

does this. 1 mark

______________________________________________ ______________________________________________ ______________________________________________


Table 5 shows the number of stomata per mm2 of epidermal tissue in three different plant species.

Stomata density

(number of stomata/mm2)

Plant species In upper epidermis In lower epidermis

A 0 0

B 412 0

C 2 436

Table 5 d. Which of the plant species listed in Table 5 is best adapted to life on a water surface?

Justify your choice. 1 mark

______________________________________________ ______________________________________________ ______________________________________________ Question 8 (4 marks) Satin bowerbirds (Ptilonorhynchus violaceus) inhabit the heavily forested and heathland areas of coastal eastern Australia from Melbourne north to central Queensland. Satin bowerbirds have an average lifespan of around 8-9 years and show highly complex courtship behaviour. When courting, the male satin bowerbird prances and struts around his bower, making a series of noises to attract as many passing females as possible. Mating occurs near the bower and the male may mate with several females in a single season. a. What type of mating system is exhibited by satin bowerbirds? Explain your answer. 1 mark

______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________ Satin bowerbirds nest between October and February, typically laying 2-3 eggs in a shallow nest of twigs built by the female. Once hatched, the female raises the young on her own. b. With reference to the information given, state whether the reproductive strategy of the

satin bowerbird would be an example of oviparity or viviparity. Give a reason for your answer. 1 mark

______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________


c. In terms of the reproductive strategies employed, is the satin bowerbird more like a R-selected strategist or a K-selected strategist? 1 mark

______________________________________________ d. State one advantage that a sexually reproducing population has over a population that

only reproduces asexually? 1 mark

______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________ Question 9 (4 marks) Water buffalo (Bubalus bubalis) were imported to Australia between 1825 and 1843. About eighty buffalo were brought to settlements on Melville Island and Coburg Peninsula to supply meat. a. What term is given to describe a species which is introduced by human actions into

places beyond its natural geographical range? 1 mark

______________________________________________ When these settlements and water buffalo were abandoned in 1949, the buffalo soon colonised the permanent and semi-permanent swamps and freshwater springs at the top end of the Northern Territory. As they made their way across the northern floodplains, the water buffalo impacted on the native wildlife and flora dramatically. Some effects of the water buffalo’s trails, dung and trampling on the ecosystems in the area include: causing high levels of soil erosion. causing flood waters to channel in specific directions. increasing the mixing of salt water into freshwater habitats. destroying wetland vegetation. Water buffalo are now considered pests, as they are solely responsible for a major environmental disaster in the wetlands at the top end of the Northern Territory. b. Select one impact of the water buffalo’s activities in the Northern Territory and

describe the effect it would have on the native wetland flora and fauna in the northern floodplains of the Northern Territory. 1 mark

______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________


Despite harvesting for meat, hides and hunters’ trophies, and an extensive eradication program in the 1980s and 1990s, feral water buffalo numbers in recent times have recovered to an estimated 150,000 and still pose an environmental threat in the areas they inhabit. c. Suggest one reason why, despite varied attempts to reduce water buffalo numbers in

the Northern Territory, their numbers still persist today. 1 mark

______________________________________________ ______________________________________________ ______________________________________________ Harvesting or culling of wildlife is a controversial topic. d. Give one reason why such an approach should not be adopted in the control of water

buffalo numbers in the Northern Territory. 1 mark

______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________

End of Section B

End of Trial Exam

Learning Materials Suggested Answers VCE Biology 2014 Year 11 Trial Exam Unit 2 1

Suggested Answers


SECTION A – Multiple Choice Answers 1. C 2. B 3. C 4. B 5. A

6. A 7. D 8. C 9. A 10. C

11. C 12. A 13. D 14. C 15. D

16. A 17. B 18. B 19. B 20. A 21. B 22. C 23. B 24. D 25. A

SECTION B –Short Answer (Answers) Question 1 (5 marks) a. Long sharp claws (1 mark). b. Feature 1: Southern subspecies possessing thicker and longer fur an advantage.

Survival advantage in winter months: Provides a greater amount of insulation than Northern subspecies which has thinner and shorter fur thus reducing heat loss in colder temperatures (1 mark). Feature 2: Larger size of Southern subspecies. Survival advantage in winter months: Being larger decreases exposed surface area of the Southern subspecies of koala relative to its volume which reduces heat loss in colder temperatures (1 mark). (Feature and survival advantage in each case needs to be correct to be awarded the 1 mark).

c. Koalas conserve energy by moving slowly and sleeping for most of the day (approximately 20 hours) (1 mark).

d. By licking their arms and stretching out as they rest in the trees, koalas are aiding heat loss by evaporative cooling and by increasing exposed surface from which this evaporation can take place (1 mark).

Question 2 (9 marks) a. Any one of the following predator-prey food chains should be awarded (1 mark).


b. i. Phytoplankton. ii. Seals (1 mark for both correct answers). iii. Zooplankton/ krill (dependent on food chain listed in 1a). iv. Small toothed whale (1 mark for both correct answers).

c.

*(1 mark for correct order in biomass pyramid) *(1 mark for correctly identifying each population)

d. Food chain: phytoplankton krill baleen whale. The krill feeds on

the phytoplankton while the baleen whale preys on the krill (1 mark). e. A second predator would decrease the number of krill (1 mark). Fewer krill feeding

on the phytoplankton will increase the phytoplankton numbers (1 mark). Competition for krill and reduced numbers of krill will also lead to a decrease in population of baleen whales (1 mark).

Question 3 (8 marks) a. Any one of the following is acceptable:

Biomolecule (1 mark) Function (1 mark) 1. ATP (adenosine triphosphate) Energy source within cells 2. DNA and/or RNA (deoxyribonucleic

acid or ribonucleic acid) DNA is responsible for storing and transferring genetic information while RNA directly codes for amino acids and acts as a messenger between DNA and ribosomes to make proteins.

3. Phospholipids Structural component of biological membranes


b. i. Being a form of matter, phosphorus is recycled within and between ecosystems via a biogeochemical cycle. The flow of energy in an ecosystem is one way. Energy is not recycled and needs to be continuously supplied from external sources as most of it is converted to heat as it moves through an ecosystem (1 mark).

ii. The phosphorus cycle is different compared to the carbon and nitrogen cycles because it does not occur naturally in the gas state in the atmosphere. Phosphorus is only found in land, water, and sediment (1 mark).

c. Phosphorus occurs as minerals in rocks (1 mark). d. Weathering and erosion of rocks and minerals release phosphorus in a soluble form

where it is taken up by plants and then transformed into organic compounds (1 mark). e. Very slow as weathering and erosion are processes which occur gradually over a long

period of time (1 mark). f. High levels of phosphorus in natural water systems promote the rapid growth of

aquatic plants (eutrophication) which can impact negatively on other organisms in the ecosystem (1 mark).

Question 4 (3 marks) Effect on organism 2 Harm Benefit No effect Effect on organism 1

Harm a) Competition b) Predation or parasitism

Benefit c) Predation or parasitism

d) Mutualism e) Commensalism

No effect f) Commensalism

(For every two correct responses 1 mark should be given for a total of 3 marks)

Question 5 (8 marks) a. A habitat is an ecological or environmental area that is inhabited by a particular

species of animal, plant, or other type of organism (1 mark). The ecological niche involves both the place where an organism lives and the roles that an organism plays in its habitat (1 mark).

b. Endemic (1 mark). c. Environment: Rainforest (1 mark).

Any one of the following is acceptable: (1 mark) * Broad leaves – as larger numbers of stomata are present, water loss isn’t a problem suggesting a moist environment. *Hairless – doesn't trap water – suggests water loss is not a major concern and therefore suggests a moist environment. *Glossy green – suggests the leaf has a cuticle which is transparent which allows maximum amount of light to pass through thus assisting photosynthesis. *Thin leaves – leaves have a large surface area to volume ratio providing absorption of sunlight and therefore suggests a dark environment.


d. "Slash and burn" agriculture leads to habitat destruction (1 mark). or

Catharanthus roseus lacks the relevant plant adaptations to resist the effects of fire (1 mark).

e. To maintain genetic diversity within species so that populations of organisms can combat diseases more effectively and successfully. If wild populations become extinct, genetic material is lost forever (1 mark).

f. Damming of rivers and diversion of water from rivers or nutrient overload of water ways and waste disposal are possible answers (1 mark).

Question 6 (5 marks) a. Logistic growth or density-dependent growth or s-shaped growth pattern (1 mark). b. As a population increases in size, pressure on resources increases and population

growth slows (D onwards) and then stops (F onwards). Factors like competition between members of the population for scarce resources can lead to starvation and overcrowding, resulting in slowing growth (1 mark).

c. C – because it is the steepest part of the graph (1 mark). d. After 8 days, a carrying capacity of 280 organisms/L for this population is reached

(1 mark). e. K-selected strategists like sharks are at a greater risk of extinction if its population

numbers fall because of their long generation times and low rates of increase. K-selected strategists are better adapted to living in stable environments with their population size at or near carrying capacity while R-selected strategists are better adapted to living in unstable environments (1 mark).

Question 7 (4 marks) a. As the transpiration rate has decreased between 26-29°C, the water lost by

transpiration equals the amount of water drained from the roots and so some stomatal pores are closing. If excessive water is lost, stomatal pores close (1 mark).

b. Rate of transpiration will decrease because the more humid the air, the more saturated with water it is. As a result the concentration difference between water vapour inside and outside a leaf would be less thus lowering transpiration rate (1 mark).

c. Any one of the following is an acceptable answer: thick waxy cuticle – reduces evaporation through the cuticle thick upper epidermal layer – reduces evaporation curvature of leaf (round lower surface) – maintains a high humidity immediately

outside the stomata sunken stomata – maintains the high humidity epidermal hairs – maintains a high humidity immediately outside the stomata low density of stomata – reduces stomata evaporation few air spaces – reduces surface area for evaporation

(1 mark). d. Species B as the presence of stomata in the upper epidermis would allow gas

exchange with the air to be possible (1 mark).


Question 8 (4 marks) a. Polygyny – one male has multiple female partners during a breeding season (1 mark). b. Oviparity because eggs are released by the mother and the embryo develops outside

the mother's body with nutrient for the embryo coming from the egg yolk (1 mark). c. K-selected strategist (1 mark). d. Advantages of sexual reproduction include: genetic variation in offspring, unique

offspring produced, organism may be more protected by parent (1 mark). Question 9 (4 marks) a. An exotic species (1 mark). b. Any one of the following effects is acceptable: (1 mark)

Impact 1: High levels of soil erosion – flora and fauna suffer from the habitat disturbance, resulting in loss of cover and therefore make them more vulnerable to predators.

Impact 2: Channelling of flood waters – flora and fauna suffer from habitat disturbance and subsequent loss of food source. Water borne diseases can also spread to native flora and fauna in the area.

Impact 3: Increased mixing of the salt water into freshwater habitats – flora dies resulting in some native wildlife losing their food source.

Impact 4: Destroying wetland vegetation – may result in spread of weeds in the area.

c. The challenging nature of the landscape or the consequent high costs of a harvesting/culling program or the absence of natural predators of water buffalo makes total eradication almost impossible (1 mark).

d. Any one of the following reasons is acceptable: (1 mark) There are alternatives to culling that could be used instead. For example relocation

of organisms or using noise making devices to deter organisms from the area to be protected.

Culling is ineffective in the long term as the species will eventually repopulate the area.

Evidence suggests that some animals can keep their own numbers down without the need for culling.

Deciding which animals live or die is interfering with the process of natural selection.

End of Suggested Answers

biology 2014 year 11 te unit 2 - quia

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