Thematic ielts reading practice tests toshkent «pir» nashriyoti – 2023 Cambridge English

Cambridge IELTS Academic 17
TEST 39 
Questions 14 – 17
Reading Passage 2 has seven paragraphs, A-G.
Which section contains the following information?
Write the correct letter,
 
A-G
, in boxes 
14-17
 on your answer sheet.
NB
You may use any letter more than once.
14
a mention of negative attitudes towards stadium building projects
15
figures demonstrating the environmental benefits of a certain stadium
16
examples of the wide range of facilities available at some new stadiums
17
reference to the disadvantages of the stadiums built during a certain era

---

85
TEST 40 READING PASSAGE 2
You should spend about 20 minutes on 
Questions 14-18
 which are based on 
Reading Passage 2 below.
A second attempt at domesticating the tomato
* mutations: changes in an organism’s genetic structure that can be passed down to later generations
A 
It took at least 3,000 years for humans 
to learn how to domesticate the wild 
tomato and cultivate it for food. Now 
two separate teams in Brazil and 
China have done it all over again in 
less than three years. And they have 
done it better in some ways, as the 
re-domesticated tomatoes are more 
nutritious than the ones we eat at 
present.
This approach relies on the 
revolutionary CRISPR genome 
editing technique, in which changes 
are deliberately made to the DNA of 
a living cell, allowing genetic material 
to be added, removed or altered. The 
technique could not only improve 
existing crops, but could also be used 
to turn thousands of wild plants into 
useful and appealing foods. In fact, 
a third team in the US has already 
begun to do this with a relative of the 
tomato called the groundcherry.
This fast-track domestication could 
help make the world’s food supply 
healthier and far more resistant to 
diseases, such as the rust fungus 
devastating wheat crops.
‘This could transform what we eat,’ 
says Jorg Kudla at the University of 
Munster in Germany, a member of 
the Brazilian team. ‘There are 50,000 
edible plants in the world, but 90 
percent of our energy comes from just 
15 crops.’
‘We can now mimic the known 
domestication course of major crops 
like rice, maize, sorghum or others,’ 
says Caixia Gao of the Chinese 
Academy of Sciences in Beijing. ‘Then 
we might try to domesticate plants that 
have never been domesticated.’
B 
Wild tomatoes, which are native to 
the Andes region in South America, 
produce pea-sized fruits. Over many 
generations, peoples such as the 
Aztecs and Incas transformed the plant 
by selecting and breeding plants with 
mutations* in their genetic structure, 
which resulted in desirable traits such 
as larger fruit.
But every time a single plant with 
a mutation is taken from a larger 
population for breeding, much genetic 
diversity is lost. And sometimes the 
desirable mutations come with less 
desirable traits. For instance, the 
tomato strains grown for supermarkets 
have lost much of their flavour.
By comparing the genomes of modern 
plants to those of their wild relatives, 
biologists have been working out 
what genetic changes occurred 
as plants were domesticated. The 
teams in Brazil and China have now 
used this knowledge to reintroduce 
these changes from scratch while 
maintaining or even enhancing the 
desirable traits of wild strains.

---

86
C 
Kudla’s team made six changes 
altogether. For instance, they tripled 
the size of fruit by editing a gene 
called FRUIT WEIGHT, and increased 
the number of tomatoes per truss by 
editing another called MULTIFLORA.
While the historical domestication of 
tomatoes reduced levels of the red 
pigment lycopene – thought to have 
potential health benefits – the team 
in Brazil managed to boost it instead. 
The wild tomato has twice as much 
lycopene as cultivated ones; the newly 
domesticated one has five times as 
much.
‘They are quite tasty,’ says Kudla. ‘A 
little bit strong. And very aromatic.’
The team in China re-domesticated 
several strains of wild tomatoes with 
desirable traits lost in domesticated 
tomatoes. In this way they managed to 
create a strain resistant to a common 
disease called bacterial spot race, 
which can devastate yields. They also 
created another strain that is more 
salt tolerant – and has higher levels 
of vitamin C.
D 
Meanwhile, Joyce Van Eck at the Boyce 
Thompson Institute in New York state 
decided to use the same approach 
to domesticate the groundcherry or 
goldenberry (Physalis pruinosa) for 
the first time. This fruit looks similar to 
the closely related Cape gooseberry 
(Physalis peruviana).
Groundcherries are already sold to a 
limited extent in the US but they are 
hard to produce because the plant 
has a sprawling growth habit and the 
small fruits fall off the branches when 
ripe. Van Eck’s team has edited the 
plants to increase fruit size, make 
their growth more compact and to 
stop fruits dropping. ‘There’s potential 
for this to be a commercial crop,’ says 
Van Eck. But she adds that taking 
the work further would be expensive 
because of the need to pay for a 
licence for the CRISPR technology 
and get regulatory approval.
E 
This approach could boost the use of 
many obscure plants, says Jonathan 
Jones of the Sainsbury Lab in the 
UK. But it will be hard for new foods 
to grow so popular with farmers and 
consumers that they become new 
staple crops, he thinks.
The three teams already have their 
eye on other plants that could be 
‘catapulted into the mainstream’, 
including foxtail, oat-grass and 
cowpea. By choosing wild plants that 
are drought or heat tolerant, says Gao, 
we could create crops that will thrive 
even as the planet warms.
But Kudla didn’t want to reveal which 
species were in his team’s sights, 
because CRISPR has made the 
process so easy. ‘Any one with the 
right skills could go to their lab and do 
this.’

---

87