READING PASSAGE 1
You should spend about 20 minutes on Questions 1–16, which
are based on Reading Passage 1 below.
How
bacteria invented gene editing
This week the UK Human Fertilisation and Embryology Authority
okayed a proposal to modify human embryos through gene editing. The research,
which will be carried out at the Francis Crick Institute in London, should
improve our understanding of human development. It will also undoubtedly
attract controversy - particularly with claims that manipulating embryonic
genomes is a first step towards designer babies. Those concerns shouldn't be
ignored. After all, gene editing of the kind that will soon be undertaken at
the Francis Crick Institute doesn't occur naturally in humans or other animals.
It is, however, a lot more common in nature than you might think,
and it's been going on for a surprisingly long time - revelations that have
challenged what biologists thought they knew about the way evolution works.
We're talking here about one particular gene editing technique called
CRISPR-Cas, or just CRISPR. It's relatively fast, cheap and easy to edit genes
with CRISPR - factors that explain why the technique has exploded in popularity
in the last few years. But CRISPR wasn't dreamed up from scratch in a
laboratory. This gene editing tool actually evolved in single-celled microbes.
CRISPR went unnoticed by biologists for decades. It was only at
the tail end of the 1980s that researchers studying Escherichia coli noticed
that there were some odd repetitive sequences at the end of one of the
bacterial genes. Later, these sequences would be named Clustered Regularly
Interspaced Short Palindromic Repeats - CRISPRs. For several years the
significance of these CRISPRs was a mystery, even when researchers noticed that
they were always separated from one another by equally odd 'spacer' gene
sequences.
Then, a little over a decade ago, scientists made an important
discovery. Those 'spacer' sequences look odd because they aren't bacterial in
origin. Many are actually snippets of DNA from viruses that are known to attack
bacteria. In 2005, three research groups independently reached the same
conclusion: CRISPR and its associated genetic sequences were acting as a
bacterial immune system. In simple terms, this is how it works. A bacterial
cell generates special proteins from genes associated with the CRISPR repeats
(these are called CRISPR associated - Cas - proteins). If a virus invades the
cell, these Cas proteins bind to the viral DNA and help cut out a chunk. Then,
that chunk of viral DNA gets carried back to the bacterial cell's genome where
it is inserted - becoming a spacer. From now on, the bacterial cell can use the
spacer to recognise that particular virus and attack it more effectively.
These findings were a revelation. Geneticists quickly realised
that the CRISPR system effectively involves microbes deliberately editing their
own genomes - suggesting the system could form the basis of a brand new type of
genetic engineering technology. They worked out the mechanics of the CRISPR
system and got it working in their lab experiments. It was a breakthrough that
paved the way for this week's announcement by the HFEA. Exactly who took the
key steps to turn CRISPR into a useful genetic tool is, however, the subject of
a huge controversy. Perhaps that's inevitable - credit for developing CRISPR
gene editing will probably guarantee both scientific fame and financial wealth.
Beyond these very important practical applications, though,
there's another CRISPR story. It's the account of how the discovery of CRISPR
has influenced evolutionary biology. Sometimes overlooked is the fact that it
wasn't just geneticists who were excited by CRISPR's discovery - so too were
biologists. They realised CRISPR was evidence of a completely unexpected
parallel between the way humans and bacteria fight infections. We've known for
a long time that part of our immune system "learns" about the pathogens it has
seen before so it can adapt and fight infections better in future. Vertebrate
animals were thought to be the only organisms with such a sophisticated
adaptive immune system. In light of the discovery of CRISPR, it seemed some
bacteria had their own version. In fact, it turned out that lots of bacteria
have their own version. At the last count, the CRISPR adaptive immune system
was estimated to be present in about 40% of bacteria. Among the other major
group of single-celled microbes - the archaea - CRISPR is even more common.
It's seen in about 90% of them. If it's that common today, CRISPR must have a
history stretching back over millions - possibly even billions - of years.
"It's clearly been around for a while," says Darren Griffin at the
University of Kent.
The animal adaptive immune system, then, isn't nearly as unique as
we thought. And there's one feature of CRISPR that makes it arguably even
better than our adaptive immune system: CRISPR is heritable. When we are
infected by a pathogen, our adaptive immune system learns from the experience,
making our next encounter with that pathogen less of an ordeal. This is why
vaccination is so effective: it involves priming us with a weakened version of
a pathogen to train our adaptive immune system. Your children, though, won't
benefit from the wealth of experience locked away in your adaptive immune
system. They have to experience an infection - or be vaccinated - first hand
before they can learn to deal with a given pathogen.
CRISPR is different. When a microbe with CRISPR is attacked by a
virus, the record of the encounter is hardwired into the microbe's DNA as a new
spacer. This is then automatically passed on when the cell divides into
daughter cells, which means those daughter cells know how to fight the virus
even before they've seen it. We don't know for sure why the CRISPR adaptive
immune system works in a way that seems, at least superficially, superior to
ours. But perhaps our biological complexity is the problem, says Griffin.
"In complex organisms any minor [genetic] changes cause profound effects
on the organism," he says. Microbes might be sturdy enough to constantly
edit their genomes during their lives and cope with the consequences - but
animals probably aren't. The discovery of this heritable immune system was,
however, a biologically astonishing one. It means that some microbes write
their lifetime experiences of their environment into their genome and then pass
the information to their offspring – and that is something that evolutionary
biologists did not think happened.
Darwin's theory of evolution is based on the idea that natural
selection acts on the naturally occurring random variation in a population.
Some organisms are better adapted to the environment than others, and more
likely to survive and reproduce, but this is largely because they just happened
to be born that way. But before Darwin, other scientists had suggested
different mechanisms through which evolution might work. One of the most famous
ideas was proposed by a French scientist called Jean-Bapteste Lamarck. He
thought organisms actually changed during their life, acquiring useful new
adaptations non-randomly in response to their environmental experiences. They
then passed on these changes to their offspring.
People often use giraffes to illustrate Lamarck's hypothesis. The
idea is that even deep in prehistory, the giraffe's ancestor had a penchant for
leaves at the top of trees. This early giraffe had a relatively short neck, but
during its life it spent so much time stretching to reach leaves that its neck
lengthened slightly. The crucial point, said Lamarck, was that this slightly
longer neck was somehow inherited by the giraffe's offspring. These giraffes
also stretched to reach high leaves during their lives, meaning their necks
lengthened just a little bit more, and so on. Once Darwin's ideas gained
traction, Lamarck's ideas became deeply unpopular. But the CRISPR immune system
- in which specific lifetime experiences of the environment are passed on to
the next generation - is one of a tiny handful of natural phenomena that
arguably obeys Lamarckian principles.
"The realisation that Lamarckian type of evolution does occur
and is common enough, was as startling to biologists as it seems to a
layperson," says Eugene Koonin at the National Institutes of Health in
Bethesda, Maryland, who explored the idea with his colleagues in 2009, and does
so again in a paper due to be published later this year. This isn't to say that
all of Lamarck's thoughts on evolution are back in vogue. "Lamarck had
additional ideas that were important to him, such as the inherent drive to
perfection that to him was a key feature of evolution," says Koonin. No
modern evolutionary biologist goes along with that idea. But the discovery of
the CRISPR system still implies that evolution isn't purely the result of
Darwinian random natural selection. It can sometimes involve elements of
non-random Lamarckism too – a "continuum", as Koonin puts it. In
other words, the CRISPR story has had a profound scientific impact far beyond
the doors of the genetic engineering lab. It truly was a transformative
discovery.
Questions 1–5
Do
the following statements agree with the information given in Reading Passage 1?
In
boxes 1–5 on your answer sheet, write
TRUE
if the statement agrees with the information
FALSE
if the statement contradicts the information
NOT GIVEN
if there is no information on this
- The research carried out at the
Francis Crick Institute in London is likely to be
controversial.
- Gene editing, like the one in
the upcoming research, can happen naturally in humans or other
animals.
- CRISPR-Cas is a gene editing
technique.
- CRISPR was noticed when the
researchers saw some odd repetitive sequences at the ends of all bacterial
genes.
- A group of American researchers
made an important revelation about the CRISPR.
Questions 6–9
Choose
the correct letter, A, B, C or D.
Write
the correct letter in boxes 6–9 on your answer sheet.
- 'Spacer' sequences look odd
because:
- they
are a bacterial immune system
- they
are DNA from viruses
- they
aren't bacterial in origin
- all
of the above
- The ones, who were excited
about the CRISPR's discovery, were:
- biologists
- geneticists
- physicists
- A
and B
- Word "learns" in the line 44, 6th paragraph means:
- determines
- gains
awarness
- adapts
- studies
- What makes CRISPR better
than even our adaptive immune system?
- long
history of existence
- immortality
- heritability
- adaptiveness
Questions 10–16
Complete
the sentences below.
Write NO MORE THAN TWO WORDS from the passage for each answer.
Write
your answers in boxes 10–16 on your answer sheet.
10. Vaccination is so effective, because it involves with
a weakened version of a pathogen .
11. CRISPR adaptive immune system works in a way that seems, at least
superficially, superior to ours. But perhaps our is the
problem, according to Griffin.
12. Some microbes write their experience into the genome and pass the
information to their .
13. Before Darwin, one of the most famous idea was proposed by a scientist,
Lamarck.
14. are often used to demonstrate
Lamarck's hypothesis.
15. Lamarck's ideas became deeply unpopular as soon as Darwin's
ideas .
16. No biologist agrees with Lamarck's
idea that inherent drive to perfection is the key feature of evolution.
READING PASSAGE 2
You
should spend about 20 minutes on Questions 17-28, which are based on Reading Passage 2 below.
Museum of Lost Objects:
The Lion of al-Lat
(A) Two thousand years ago a statue of a lion
watched over a temple in the ancient Syrian city of Palmyra. More recently,
after being excavated in the 1970s, it became an emblem of the city and a favourite
with tourists. But it was one of the first things destroyed during military
fightings in the country. It's said that there are more than 300 words for lion
in Arabic. That's a measure of the importance of the lion in the history of the
Middle East. For Bedouin tribes, the lion represented the biggest danger in the
wild - until the last one in the region died, some time in the 19th Century.
(B) The animal was feared and admired and this
must explain why a statue of a lion twice as high as a human being, weighing 15
tonnes, was fashioned by artists in ancient Palmyra. With spiralling, somewhat
loopy eyes, and thick whiskers swept back angrily along its cheek bones, the
lion was clearly a fighter, but it was also a lover. In between its legs, it
held a horned antelope. The antelope stretched a delicate hoof over the lion's
monstrous paws, and perhaps it was safe. The lion was a symbol of protection -
it was both marking and protecting the entrance to the temple. But no-one could
protect the lion when *IS arrived and wrecked it in May 2015. "It was a
real shock, because you know, in a way, it was our lion," says Polish
archaeologist Michal Gawlikowski, whose team unearthed it in 1977.
(C) For well over 1,000 years, the statue had lain
buried in the ruins of the ancient city, though parts had been used as
foundations stones in other buildings. "You could hardly see what it was.
I could see it was a sculpture and an old one for Palmyra, so we decided it was
necessary to put it together immediately. It wasn't apparent from the beginning
what this was - and then we found the head, and it became obvious."
(D) Here are 30 of the approximately 300
Arabic words for "lion": Ghazhanfar, haidera, laith, malik al-ghaab
(king of the jungle), qasha'am, asumsum, hatam, abu libdeh, hamza, nebras,
basel, jasaas, assad, shujaa, rihab, seba'a, mayyas, khunafis, aabas, aafras,
abu firas, qaswarah, ward, raheeb, ghadi, abu harith, dargham, hammam, usama,
jaifer, qasqas... Most describe different moods of the lion. For example, hatam
the destroyer, rihab the fearsome, ghazhanfar the warrior, abu libdeh the one
with the fur, or the mane. As luck would have it, Michal had on his team that
year the sculptor Jozef Gazy, who enthusiastically took on the job of restoring
the lion. By 2005, though, the lion had become unbalanced and another
restoration job - again led by a Polish team - rebuilt the statue to resemble
as closely as possible what is thought to be the ancient design, with the lion
appearing to leap out of the temple wall. After this it was placed in front of
the Palmyra museum.
(E) Across the left paw of the lion is a
Palmyrene inscription: "May al-Lat bless whoever does not spill blood on
this sanctuary." The goddess al-Lat was a pre-Islamic female deity popular
throughout Arabia, the descendant of earlier Mesopotamian goddesses such as
Ishtar Inanna. "Ishtar Inanna is goddess of warfare and also love and sex,
particularly sex outside marriage," says Augusta McMahon, lecturer of
archaeology at Cambridge University. Al-Lat shared most of these attributes,
and like Ishtar Inanna she was associated with lions. "It's very
interesting to find a lion and a female figure in such close association, and
no male deities have the lion - so this is something which is unique to
her," says McMahon.
(F) The region's kings, however, were keen to
be associated with lions, even if male deities weren't. Some of the earliest
known representations of Mesopotamian leaders, from around 3,500 BC, depict
them engaged in combat with the creatures. "They're not shown fighting or
killing other people because that's almost demeaning," says Augusta
McMahon. "They have to have a lion who is the not-quite-equal-but-near
rival - because they're incredibly powerful and sort of unpredictable."
This tradition continues right up to the medieval and early modern period, when
Islamic miniatures would often show scenes of the hunt, of brave princes struggling
with lions. The lion was both regal and untameable, the quintessence of
strength and man's ultimate opponent. And today, fathers still love to name
their sons and heirs after this fearsome predator - Osama for example.
(G) The family of Syria's current ruling
dynasty went even further. Al-Assad means "the lion" and different
stories are told about how, a few generations ago, they adopted this name. One
version says that Sulayman, great-grandfather of current president Bashar
al-Assad, had been given the name al-Wahhish, or "the wild beast",
because of his exploits while waging war on the Ottomans. This had negative
connotations, though - so Sulayman swapped al-Wahhish for al-Assad "the
lion". In neighbouring Iraq, Saddam Hussein even more directly channelled
the rulers of times gone by. Some of his fanciful propaganda - often seen in
newspapers or even city billboards - would show him posing as an Assyrian king,
trampling on lions while shooting at American missiles with a bow and arrow.
(H) But Saddam didn't have full control over
his lion symbolism. One of the many words referring to lion in Arabic can
connote "brazenness" and "audacity", and it was this
lion-word that many Iraqis applied to him. "The lion has several names and
one of them is seba'a," says the Iraqi archaeologist Lamia al-Gailani.
"It was considered one the worst things in the culture of the Iraqis this
word seba'a because it gives license to be corrupt. When Saddam did things,
people said [they were] seba'a and what he did was so wrong, so illegal, but he
was able to get away with it."
(I) For most people who went to Palmyra, the
Lion of al-Lat provided a key photo opportunity. For London-based Syrian
sculptor Zahed Tajeddin, it also provided artistic inspiration. In the early
1990s Tajeddin held an exhibition in Germany where he produced miniature
sculptures of his favourite archaeological monuments from Syria - including the
lion - but by 2015 all had been sold. Fatefully, though, during the week in May
2015 when IS took Palmyra and destroyed the Lion of al-Lat, he found the
moulds.
(J) "And I thought, OK, that's a message,"
he says. "And so I reproduced three and put them next to each other and I
painted them in white, red and black to represent the Syrian flag." The
lion was often a symbol of vanity and masculine power. It was the badge of
self-aggrandising kings and presidents. But in Tajeddin's reproductions of the
lion of al-Lat, the lion becomes something else - a protest against the
devastation engulfing his country and its ancient heritage.
*IS
- Islamic State (of Iraq and the Levant), a terrorist organisation.
Questions 17–25
Reading
Passage 2 has ten paragraphs, A-J.
Which
paragraph contains the following information?
Write
the correct letter, A-J, in boxes 17-25 on your
answer sheet. Note that one paragraph is not used.
17. Goddess, associated with lions
18. One of the worst words
19. An emblem of the city
20. History of the family name
21. Art exhibition
22. The description of the lion statue
23. Symbolic meaning of the lion's reproduction by Tajeddin
24. Synonyms for word lion
25. Representations of leaders
Questions 26–28
Complete
the sentences below.
Write NO MORE THAN TWO WORDS from the passage for each answer.
Write
your answers in boxes 26–28 on your answer sheet.
26. Most words for the lion describe different of
the animal.
27. You could often see struggling with
lions in Islamic miniatures.
28. The Lion of al-Lat provided an for
sculptor Zahed Tajeddin.
You
should spend about 20 minutes on Questions 29–40, which are based on Reading Passage 3 below.
The Truth About ART
Modern
art has had something of a bad press recently - or, to be more precise, it has
always had a bad press in certain newspapers and amongst certain sectors of the
public. In the public mind, it seems, art (that is, graphic art - pictures -
and spatial art - sculpture) is divided into two broad categories. The first is
'classic' art, by which is meant representational painting, drawing and
sculpture; the second is 'modern' art, also known as abstract or
non-representational. British popular taste runs decidedly in favour of the
former, if one believes a recent survey conducted by Charlie Moore, owner of
the Loft Gallery and Workshops in Kent, and one of Britain's most influential
artistic commentators. He found that the man (or woman) in the street has a distrust
of cubism, abstracts, sculptures made of bricks and all types of so-called
'found' art, He likes Turner and Constable, the great representatives of
British watercolour and oil painting respectively, or the French
Impressionists, and his taste for statues is limited to the realistic figures
of the great and good that litter the British landscape - Robin Hood in
Nottingham and Oliver Cromwell outside the Houses of Parliament. This everyman
does not believe in primary colours, abstraction and geometry in nature - the
most common comment is that such-and-such a painting is "something a child
could have done".
Lewis
Williams, director of the Beaconsfield Galleries in Hampshire, which
specialises in modern painting, agrees. "Look around you at what art is available
every day," he says. "Our great museums and galleries specialise in
work which is designed to appeal to the lowest common denominator. It may be
representational, it may be 'realistic' in one sense, but a lot of it wouldn't
make it into the great European galleries. Britain has had maybe two or three
major world painters in the last 1000 years, so we make up the space with a lot
of second-rate material."
Williams
believes that our ignorance of what modern art is has been caused by this lack
of exposure to truly great art. He compares the experience of the average
British city-dweller with that of a citizen of Italy, France or Spain.
"Of
course, we don't appreciate any kind of art in the same way because of the
paucity of good art in Britain. We don't have galleries of the quality of those
in Madrid, Paris, Versailles, Florence, New York or even some places in Russia.
We distrust good art - by which I mean both modern and traditional artistic
forms - because we don't have enough of it to learn about it. In other
countries, people are surrounded by it from birth. Indeed they take it as a
birthright, and are proud of it. The British tend to be suspicious of it. It's
not valued here."
Not
everyone agrees. Emily Cope, who runs the Osborne Art House, believes that
while the British do not have the same history of artistic experience as many
European countries, their senses are as finely attuned to art as anyone else's.
"Look
at what sells - in the great art auction houses, in greetings cards, in
posters. Look at what's going on in local amateur art classes up and down the
country. Of course, the British are not the same as other countries, but that's
true of all nationalities. The French artistic experience and outlook is not
the same as the Italian. In Britain, we have artistic influences from all over
the world. There's the Irish, Welsh, and Scottish influences, as well as
Caribbean, African and European. We also have strong links with the Far East,
in particular the Indian subcontinent. All these influences come to bear in
creating a British artistic outlook. There's this tendency to say that British
people only want garish pictures of clowns crying or ships sailing into battle,
and that anything new or different is misunderstood. That's not my experience at
all. The British public is poorly educated in art, but that's not the same as
being uninterested in it."
Cope
points to Britain's long tradition of visionary artists such as William Blake,
the London engraver and poet who died in 1827. Artists like Blake tended to be
one-offs rather than members of a school, and their work is diverse and often
word-based so it is difficult to export.
Perhaps,
as ever, the truth is somewhere in between these two opinions. It is true that
visits to traditional galleries like the National and the National Portrait
Gallery outnumber attendance at more modern shows, but this is the case in
every country except Spain, perhaps because of the influence of the two most
famous non-traditional Spanish painters of the 20th century, Picasso and Dali.
However, what is also true is that Britain has produced a long line of
individual artists with unique, almost unclassifiable styles such as Blake,
Samuel Palmer and Henry Moore.
Questions 29–37
Classify
the following statements as referring to
A Charlie Moore
B Lewis Williams
C Emily Cope
Write
the appropriate letters A, B or C in boxes 29-37 on your answer sheet.
29. British people don't appreciate art because they don't see enough
art around them all the time.
30. British museums aim to appeal to popular tastes in art.
31. The average Englishman likes the works of Turner and
Constable.
32. Britain, like every other country, has its own view of what art
is.
33. In Britain, interest in art is mainly limited to traditional
forms such as representational painting.
34. British art has always been affected by other
cultures.
35. Galleries in other countries are of better quality that
those in Britain.
36. People are not raised to appreciate art.
37. The British have a limited knowledge of art.
Questions 38–40
Choose
the correct letter, A, B, C or D.
Write
the correct letter in boxes 38-40 on your answer sheet.
- Many British artists
- are
engravers or poets
- are
great but liked only in Britain
- do
not belong to a school or general trend
- are
influenced by Picasso and Dali
- Classic' art can be described
as
- sentimental,
realistic paintings with geometric shapes
- realistic
paintings with primary colours
- abstract
modern paintings and sculptures
- realistic,
representational pictures and sculptures
- In Spain, people probably enjoy
modern art because
- their
artists have a classifiable style
- the
most renowned modern artists are Spanish
- they
attend many modern exhibitions
- they
have different opinions on art
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