A Second Attempt At Domesticating The Tomato Reading Answers: The reading passage A Second Attempt At Domesticating The Tomato explores recent scientific advances in crop domestication using the CRISPR genome editing technique. This innovative approach enables researchers to modify the DNA of plants precisely and rapidly, allowing the restoration and improvement of desirable traits lost through traditional breeding. The IELTS Reading passage focuses on how teams from Brazil, China, and the United States have successfully re-domesticated tomatoes and related plants to enhance nutrition, yield, and disease resistance. The following questions test your understanding of key details, matching headings to paragraphs, information location, and sentence completion skills based on the passage.
Free IELTS Reading Practice Tests
A Second Attempt At Domesticating The Tomato Reading Answers Passage
You should spend about 20 minutes on questions 1-13, which are based on the Reading Passage below.
A Second Attempt At Domesticating The Tomato
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. 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. Sometimes the desirable mutations come with less desirable traits. For instance, the tomato strains grown for supermarkets have lost much of their flavor.
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.
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 stop fruits from 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 license 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. ‘Anyone with the right skills could go to their lab and do this.’
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A Second Attempt At Domesticating The Tomato Reading Answers Sample Questions
Questions 1–5
Matching Headings to Paragraphs
Choose the correct heading for each paragraph from the list of headings below.
Write the correct number (i–viii) in boxes 1–5 on your answer sheet.
List of Headings
i. The challenges of turning new foods into dietary staples
ii. Improving both quantity and quality through gene editing
iii. Rediscovering ancient cultivation methods
iv. How a formerly ignored fruit is being improved
v. The benefits of editing genes in a popular crop
vi. Comparing historical and modern domestication
vii. CRISPR’s role in future food security
viii. Using DNA evidence to reintroduce favourable traits
1. Paragraph A
2. Paragraph B
3. Paragraph C
4. Paragraph D
5. Paragraph E
Questions 6–10
Matching Information
You should spend about 20 minutes on Questions 6–13, which are based on the Reading Passage above.
Which paragraph contains the following information?
Write the correct letter A–E in boxes 6–10 on your answer sheet.
You may use any letter more than once.
6. A description of how a disease-resistant tomato was developed
7. A reference to why past domestication reduced flavour
8. A comparison between cultivated and wild tomato nutrition
9. An example of CRISPR being applied to a plant not yet domesticated
10. The number of genetic changes made to improve tomato size and quantity
Questions 11–13
Sentence Completion
Complete the sentences below using NO MORE THAN TWO WORDS from the passage.
Write your answers in boxes 11–13 on your answer sheet.
11. CRISPR allows scientists to make precise changes to a plant’s __________.
12. Kudla’s team managed to increase tomato yield by editing a gene named __________.
13. A benefit of using wild plants is that some are __________ to extreme conditions.
A Second Attempt At Domesticating The Tomato Reading Answers with Explanations
1. Paragraph A - vii. CRISPR’s role in future food security
Location: Entire paragraph
Explanation: Paragraph A discusses the use of CRISPR in re-domesticating the tomato and other plants, highlighting the potential benefits for global food supplies. This aligns with the heading about CRISPR’s role in future food security.
2. Paragraph B - viii. Using DNA evidence to reintroduce favourable traits
Location: "By comparing the genomes..."
Explanation: Paragraph B talks about how scientists compared modern plant DNA with wild relatives to selectively reintroduce favourable traits. Hence, this matches heading viii.
3. Paragraph C - ii. Improving both quantity and quality through gene editing
Location: "Kudla’s team made six changes altogether..."
Explanation: This paragraph outlines how scientists edited genes to increase fruit size, number, and lycopene content. It reflects improvements in both quantity and quality using gene editing.
4. Paragraph D - iv. How a formerly ignored fruit is being improved
Location: "Meanwhile, Joyce Van Eck... decided to use the same approach..."
Explanation: It describes how the groundcherry—a lesser-known fruit—is being enhanced with CRISPR, making heading iv the best fit.
5. Paragraph E - i. The challenges of turning new foods into dietary staples
Location: "But it will be hard for new foods to grow so popular..."
Explanation: This paragraph focuses on the difficulty of making obscure or new plants mainstream, matching heading i.
6. A description of how a disease-resistant tomato was developed - Paragraph C
Location: "They also created another strain that is more salt tolerant..."
Explanation: The Chinese team used CRISPR to create a tomato strain resistant to bacterial spot race, a common disease.
7. A reference to why past domestication reduced flavour - Paragraph B
Location: "the tomato strains grown for supermarkets have lost much of their flavour."
Explanation: This mentions how selecting certain traits in the past unintentionally reduced flavour.
8. A comparison between cultivated and wild tomato nutrition - Paragraph C
Location: "The wild tomato has twice as much lycopene... the newly domesticated one has five times as much."
Explanation: The paragraph compares lycopene levels in wild, cultivated, and re-domesticated tomatoes.
9. An example of CRISPR being applied to a plant not yet domesticated - Paragraph D
Location: "Van Eck’s team has edited the plants... to domesticate the groundcherry..."
Explanation: The groundcherry had never been domesticated before, making it a clear example.
10. The number of genetic changes made to improve tomato size and quantity - Paragraph C
Location: "Kudla’s team made six changes altogether..."
Explanation: It clearly states that six genetic changes were made.
11. CRISPR allows scientists to make precise changes to a plant’s - DNA
Location: "changes are deliberately made to the DNA of a living cell..."
Explanation: CRISPR edits the DNA directly.
12. Kudla’s team managed to increase tomato yield by editing a gene named - MULTIFLORA
Location: "increased the number of tomatoes per truss by editing another called MULTIFLORA"
Explanation: The gene MULTIFLORA was responsible for increasing tomato quantity.
13. A benefit of using wild plants is that some are - drought or heat-tolerant
Location: "By choosing wild plants that are drought or heat-tolerant..."
Explanation: These traits make wild plants suitable for climate-resilient crops.
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