Passage 1: Gold dusters (13 questions)

They are the Earth's pollinators and they come in more than 200,000 shapes and sizes.

A Row upon row, tomato plants stand in formation inside a greenhouse. To reproduce, most flowering plants depend on a third
party to transfer pollen between their male and female parts. Some require extra encouragement to give up that golden dust.
The tomato flower, for example, needs a violent shake, a vibration roughly equivalent to 30 times the pull of Earth's gravity,
explains Arizona entomologist Stephen Buchmann. Growers have tried numerous ways to rattle pollen from tomato blossoms.
They have used shaking tables, air blowers and blasts of sound. But natural means seem to work better.

B It is no surprise that nature's design works best. What's astonishing is the array of workers that do it: more than 200,000
individual animal species, by varying strategies, help the world's 240,000 species of flowering plants make more flowers. Flies
and beetles are the original pollinators, going back to when flowering plants first appeared 130 million years ago. As for bees,
scientists have identified some 20,000 distinct species so far. Hummingbirds, butterflies, moths, wasps and ants are also up to
the job. Even non-flying mammals do their part: sugar-loving opossums, some rainforest monkeys, and lemurs in Madagascar, all
with nimble hands that tear open flower stalks and furry coats to which pollen sticks. Most surprising, some lizards, such as
geckos, lap up nectar and pollen and then transport the stuff on their faces and feet as they forage onward.

C All that messy diversity, unfortunately, is not well suited to the monocrops and mega-yields of modern commercial farmers.
Before farms got so big, says conservation biologist Claire Kremen of the University of California, Berkeley, 'we didn't have to
manage pollinators. They were all around because of the diverse landscapes. Now you need to bring in an army to get
pollination done.' The European honeybee was first imported to the US some 400 years ago. Now at least a hundred commercial
crops rely almost entirely on managed honeybees, which beekeepers raise and rent out to tend to big farms. And although
other species of bees are five to ten times more efficient, on a per-bee basis, at pollinating certain fruits, honeybees have bigger
colonies, cover longer distances, and tolerate management and movement better than most insects. They're not picky - they'll
spend their time on almost any crop. It's tricky to calculate what their work is truly worth; some economists put it at more than
$200 billion globally a year.

D Industrial-scale farming, however, may be wearing down the system. Honeybees have suffered diseases and parasite
infestations for as long as they've been managed, but in 2006 came an extreme blow. Around the world, bees began to
disappear over the winter in massive numbers. Beekeepers would lift the lid of a hive and be amazed to find only the queen and
a few stragglers, the worker bees gone. In the US, a third to half of all hives crashed; some beekeepers reported colony losses
near 90 percent. The mysterious culprit was named colony collapse disorder (CCD) and it remains an annual menace - and an
enigma.

E When it first hit, many people, from agronomists to the public, assumed that our slathering of chemicals on agricultural fields
was to blame for the mystery. Indeed, says Jeff Pettis of the USDA Bee Research Laboratory, 'we do find more disease in bees
that have been exposed to pesticides, even at low levels.' But it is likely that CCD involves multiple stressors. Poor nutrition and
chemical exposure, for instance, might wear down a bee's immunities before a virus finishes the insect off. It's hard to tease
apart factors and outcomes, Pettis says. New studies reveal that fungicides - not previously thought toxic to bees - can interfere
with microbes that break down pollen in the insects' guts, affecting nutrient absorption and thus long-term health and
longevity. Some findings pointed to viral and fungal pathogens working together. 'I only wish we had a single agent causing all
the declines,' Pettis says, 'that would make our work much easier.'

F However, habitat loss and alteration, he says, are even more of a menace to pollinators than pathogens. Claire Kremen
encourages farmers to cultivate the flora surrounding farmland to help solve habitat problems. 'You can't move the farm,' she
says, 'but you can diversify what grows in its vicinity: along roads, even in tractor yards.' Planting hedgerows and patches of
native flowers that bloom at different times and seeding fields with multiple plant species rather than monocrops 'not only is
better for native pollinators, but it's just better agriculture,' she says. Pesticide-free wildflower havens, adds Buchmann, would
also bolster populations of useful insects. Fortunately, too, 'there are far more generalist plants than specialist plants, so there's
a lot of redundancy in pollination,' Buchmann says. 'Even if one pollinator drops out, there are often pretty good surrogates left
to do the job.' The key to keeping our gardens growing strong, he says, is letting that diversity thrive.

G Take away that variety, and we'll lose more than honey. 'We wouldn't starve,' says Kremen. 'But what we eat, and even what
we wear - pollinators, after all, give us some of our cotton and flax - would be limited to crops whose pollen travels by other
means. 'In a sense,' she says, 'our lives would be dictated by the wind.' It's vital that we give pollinators more of what they need
and less of what they don't, and ease the burden on managed bees by letting native animals do their part, say scientists.
Questions 1-7: The reading passage has seven sections, A–G. Write the correct heading (i, ii, iii, ...) for each section from the
list of headings below.

List of Headings
i. Looking for clues
1. Section A ___ ii. Blaming the beekeepers
2. Section B ___ iii. Solutions to a more troublesome issue
3. Section C ___ iv. Discovering a new bee species
4. Section D ___ v. An impossible task for any human
5. Section E ___ vi. The preferred pollinator
6. Section F ___ vii. Plant features designed to suit the pollinator
7. Section G ___ viii. Some obvious and less obvious pollen carriers
ix. The undesirable alternative
x. An unexpected setback

Questions 8–11: Complete the sentences below. Choose NO MORE THAN THREE WORDS from the passage for each answer.

8 Both ______ were the first creatures to pollinate the world’s plants.

9 Monkeys transport pollen on their ______.

10 Honeybees are favoured pollinators among bee species partly because they travel ______.

11 A feature of CCD is often the loss of all the ______.

Questions 12–13: Choose TWO letters, A–E. Which TWO methods of combating the problems caused by CCD and habitat loss are
mentioned in the article?

A using more imported pest controllers

B removing microbes from bees’ stomachs

C cultivating a wide range of flowering plants

D increasing the size of many farms

E placing less reliance on honeybees

Some species are crucial when it comes to maintaining a well-balanced ecosystem.

A In the world of wildlife conservation, it is usually animals like whales and tigers which get the most public attention. Consequently, projects
to protect these so-called ‘flagship species’ receive the greatest amount of funding, and this helps to ensure, or at least improve the chances
of, their long-term survival. However, it could be argued that perhaps we should be focusing more attention elsewhere. This is because many
of the minute plants, insects and microorganisms that we tend to ignore actually play a far more important role in biodiversity protection.
Consider, for example, the Western honeybee Apis mellifera. Regarded as one of the world’s most efficient pollinators, the honeybee plays a
direct or indirect part in the production of many food products in our markets and stores. However, in recent years, a problem known as
‘colony collapse disorder’ has manifested itself, and now honeybee colonies are rapidly disappearing. Nobody knows the cause of this
phenomenon, but the implications are worryingly clear: unless a solution to colony collapse disorder is found soon, food production will be
seriously, perhaps disastrously, affected.

B The honeybee example illustrates how everything in the natural world is connected, and how the disappearance of one species can have a
profound effect on the ecosystem around it. To understand how this happens, imagine an arched doorway or window in an ancient stone
building. Many buildings containing arches are still standing today, hundreds, or even thousands, of years after they were built, in spite of the
ravages of time and natural disasters such as earthquakes and floods. If you examine one of the arches carefully, you will see the reason why.
On each side of the arch, there is a vertical series of bricks which gradually curve inwards, and these are supported at the centre by a
keystone. It is this keystone that gives the arch, and the structure around it, its strength and stability. Once the keystone is put in position, the
arch can stand indefinitely. Remove it, however, and the whole thing collapses.

C In the same way that an archway relies on its keystone to stay standing, so the ecosystem in a particular area relies on certain species in
order to continue functioning. Named ‘keystone species’ by zoologist Robert Paine, who undertook the first major study of the effect of
species loss on local environments, they have a major influence on the ecosystem around them. And there are a surprisingly large variety of
them. Some are carnivores and some are herbivores. Some are marine and some are terrestrial. Some, like the huge, majestic African
elephant, dominate their landscape, while others, like tiny microorganisms, are invisible to the human eye.

D At first glance, it is hard to imagine how the disappearance of one of these species could have such an effect on its environment. However,
as Paine discovered when he carried out a series of experiments in the 1960s, the impact can be extreme. The subject of his first study was
the starfish Pisaster ochraceous. When Paine removed a large number of these fish from part of Mukka Bay in the USA, he observed sudden
changes in species diversity. The mussel and sea urchin population increased, since these creatures form an important part of Pisaster’s diet.
However, other species saw a dramatic decline. Paine counted fifteen species at the beginning of his experiment, but only eight remained at
the end. Furthermore, reefs in the area were also destroyed, as increasing numbers of sea urchins fed on their coral. In another area of the
bay, where the starfish community was left undisturbed, no changes were observed. Paine also observed that once Pisaster was returned to
the area he had removed it from, the ecosystem began a gradual return to its pre-experiment state. His experiment prompted ecologists and
conservation biologists around the world to identify other keystone species using similar removal experiments to find them. Over the next
thirty years, the list of keystone species increased rapidly.

E Unfortunately, significant changes in other interconnected populations are taking place without removal experiments being carried out,
with some keystone species being driven close to extinction. For the last ten years, Professor David Gomm of the Marine Conservation
Association has led a study of sea otters in the North Pacific. This keystone predator feeds on sea urchins, which in turn feed on the vast kelp
forests in the region. ‘At the beginning of our study, sea otters were very common in the area, and so the kelp forests were thick and healthy,’
says Professor Gomm. ‘However, for a number of reasons, killer whales have begun to include otters in their diet, and this has caused sea
otter populations to fall rapidly. Consequently, sea urchin populations have exploded, and this has led to an almost total destruction of the
kelp forests.’ He believes that if sea otters become extinct, other species will follow. ‘The ecosystem would be changed forever,’ he warns.

F Professor Gomm’s prediction may sound overly dramatic to environmental sceptics, but there is an indication that it might already have
happened. The species in question is, or rather was, the dodo, a large, flightless bird that once lived on the island of Mauritius. In the late
sixteenth century, the bird’s population began to fall sharply as European settlers arriving on the island cut down the forest where they lived
and introduced dogs, cats and rats, which raided their nests for their eggs. By the end of the seventeenth century, the dodo was extinct.
Today, it is often regarded as little more than a rather slow-witted bird that was unable to adapt. However, there are some who believe it may
have been a keystone species. For evidence of this, they point to a tree called the tambalacoque. Once common across Mauritius, there are
now only a few dozen left at most. It is thought that the dodo ate the fruit of the tambalacoque and activated the seed through unique
digestive processes. With the demise of the dodo, tambalacoque numbers declined to just a few trees, reducing a valuable food source for
other animals on the island.

G Some scientists are doubtful about the connection between the dodo and the tambalacoque. After all, they argue, if the tree was
dependent on the dodo, why are there still some growing on the island? However, they all agree that even if there is no direct connection,
the study does help to make an important point: even though a species may seem unimportant in isolation, it may actually form an important
part of a much larger system of organisms, and its disappearance could have far-reaching consequences. It is therefore essential that, for the
sake of the environment, ecologists continue to identify and preserve keystone species.
Questions 1-7: The reading passage has seven sections, A–G. Write the correct heading (i, ii, iii, ...) for each section from the list of
headings below.

List of Headings
i When human intervention is not a factor
1. Section A ___ ii Testing the theory
2. Section B ___ iii The dominance of carnivorous keystone species
3. Section C ___ iv It’s the small things that matter
4. Section D ___ v Putting knowledge to practical use
5. Section E ___ vi An argument that has divided the scientific community
6. Section F ___ vii A wide variety of shapes and sizes
7. Section G ___ viii Why bees are disappearing
ix A man-made structure reflects nature
x Re-examining an old case

Questions 8–11: Complete the sentences below. Choose NO MORE THAN THREE WORDS from the passage for each answer.

8 Scientists fear that, in the near future, the unexplained disappearance of honeybees will affect the ecosystem and have a
major impact on ______.

9 The arches on old buildings rely on keystones for their ______.

10 A ______ in the numbers of some species in Mukka Bay occurred following Robert Paine’s removal experiment.

11 Kelp forests in the North Pacific have almost disappeared as an indirect result of ______ falling.

Questions 12-13: Choose and write TWO letters, A–E. Which TWO reasons does the passage give for dodos becoming extinct?

A Humans altered their natural habitat.

B Their eggs were eaten by European settlers.

C Other animals preyed on unborn birds.

D They were too slow to avoid hunters.

E One of their main food supplies died out.