Mutual Harm Reading Answers for IELTS

Smruti Das

14 min read

Updated On Nov 06, 2023

Reading Passage
Mutual Harm Reading Answers with Explanations
Tips for Answering the Question Types in the Mutual Harm Reading Passage

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The Reading Module can be the top-scoring category for IELTS aspirants, with diligent practice. To score well, you must understand how to approach and answer the different question types in the Reading Module. Ideally, you should not spend more than 20 minutes on a passage.

The Academic passage, Mutual Harm, is a reading passage that appeared in an IELTS Test. Try to find the answers to get an idea of the difficulty level of the passages in the actual reading test. If you want more passages to solve, try taking one of our IELTS reading practice tests.

So, let’s see how easy this passage is for you and if you’re able to make it in 20 minutes.

The question types found in this passage are:

Check Out: IELTS Reading Tips and Techniques to Increase your Reading Speed!

Reading Passage

You should spend about 20 minutes on Questions 1-14, which are based on the Reading Passage below.

Mutual Harm

A In forests and fields all over the world, plants are engaged in a deadly chemical war to suppress other plants and create conditions for their own success. But what if we could learn the secrets of these plants and use them for our own purpose? Would it be possible to use their strategies and weapons to help us improve agriculture by preventing weeds from germinating and encouraging growth in crops? This possibility is leading agriculture researchers to explore the effects plants have on other plants with the aim of applying their findings to farming.

B The phenomenon by which an organism produces one or more chemicals that influence the growth, survival and reproduction of other organisms is called allelopathy. These chemicals are a subset of chemicals produced by organisms called secondary metabolites. A plant primary metabolite is associated with growth and development. Allelochemicals, however, are part of plants’ defence system and have a secondary function in the life of organisms. The allelopathy comes from the Greek : allele and pathy meaning ‘mutual harm’. The term was first used by Austrian scientist Hans Molisch in 1937, but people have been noting the negative effects that one plant can have on another for a long time. In 300 BC, the Greek philosopher Theophrastus noticed that pigweed had a negative effect. In China, around the first century AD, author of Shennong Ben Cao Jing described 267 plants that have the ability to kill pests.

C Allelopathy can be observed in many aspects of plant ecology. It can affect where certain species of plant grow, the fertility of competitor plants, the natural change of plant communities over time, which plant species are able to dominate a particular area, and the diversity of plants in an area. Plants can release allelopathic chemicals in several ways: their roots can release chemicals directly into the soil , and their bark and leaves can release chemicals into the soil as they rot. Initially, scientists were interested in the negative effects of allelopathic chemicals. Observations of the phenomenon included poor growth of some forest trees, damage to crops, changes in vegetation patterns and, interestingly, the occurrence of weed–free areas. It was also realised that some species could have beneficial effects on agricultural crop plants and the possible application of allelopathy became the subject of research.

D Today research is focused on the effects of weeds on crops, the effects of crops on weeds, and how certain crops affect other crops. Agricultural scientists are exploring the use of allelochemicals to regulate growth and to act as natural herbicides, thereby promoting sustainable agriculture by using these natural chemicals as an alternative to man-made chemicals. For example, a small fast-growing tree found in Central America, sometimes called ‘miracle tree’, contains a poison that slows the growth of other trees but does not affect its own seeds. Chemicals produced by this tree have been shown to improve the production of rice. Similarly, box elder – another tree – stimulates the growth of bluestem grass, which is tall prairie grass found in the mid-western United States. Many weeds may use allelopathy to become ecologically successful; a study in China found that 25 out of 33 highly poisonous weeds had significant allelopathic properties.

E There may be at least three applications of allelopathy to agriculture. Firstly, the allelopathic properties of wild or cultivated plants may be bred into crop plants through genetic modification or traditional breeding methods to improve the release of desired allelochemicals and thus improve crop yield. Secondly, a plant with strong allelopathic properties could be used to control weeds by planting it in rotation with an agriculture crop and then leaving it to rot and become part of the soil in order to inhibit the growth of weeds. Finally, naturally occurring allelopathic chemicals could be used in combination with man-made chemicals. Boosting the efficiency of man-made herbicides could lead to reduction in the amount of herbicides used in agriculture, which is better for the environment.

F Despite the promising uses of allelopathic chemicals, agricultural scientists are still cautious. Firstly, allelopathic chemicals may break down and disappear in the soil more easily than artificial chemicals. Secondly, allelopathic chemicals may be harmful to plants other than weeds. Thirdly, allelopathic chemicals could persist in the soil for a long time and may affect crops grown in the same field as the allelopathic plants at a later date. Because the effects of allelopathic chemicals are not yet fully known, agriculture scientists will need to continue to study the biological war between plants.

Questions 1- 5

Reading Passage has six paragraphs, A-F.

Choose the correct heading for paragraphs B-F from the list of headings below.

Write the correct number, i-ix, next to questions 1-5.

List of Headings

What are metabolites?
The negative effects of allelopathy
Biological warfare in the plant world
Why we cannot use allelopathic chemicals at present
What is allelopathy?
The reasons why plants compete with other plants
The effects of allelopathy and realization of its possible uses
How could we use allelopathic chemicals in farming?
Specific examples of allelopathic plants

1 Paragraph B

2 Paragraph C

3 Paragraph D

4 Paragraph E

5 Paragraph F

Questions 6-9

Choose the correct letter, A, B, C or D.

6 What does the term ‘Allelopathy’ refer to?

A the growth and development of a plant

B the relationship between plants and grown in the same area

C the effects of chemicals produced by a plant on another plant

D a plant’s primary metabolic processes

7 Which of the following does allelopathy NOT affect?

A how certain species of plants change the nature of the soil where they grow

B the diversity of plants in an area

C the nutrients present in the soil.

D the negative effects of weeds.

8 Scientists are mainly interested in

A being able to exploit allelopathy in sustainable farming.

B the beneficial effects of weeds on crops.

C the effect of allelopathy on forests.

D the negative effects of weeds.

9 Which of the following is NOT mentioned in the text?

A a tree which is highly poisonous to weeds

B a tree which makes a type of grass grow better

C a tree which makes rice more productive

D a tree which produces a chemical that affects the growth of other trees

Questions 10-14

Complete the summary of paragraphs E and F below.

Choose NO MORE THAN TWO WORDS from the passage of each answer.

Write your answer in spaces 10-14.

Scientists can see three potential uses of allelopathic chemicals in farming. Firstly, the ability to produce allelopathic chemicals could be 10………………………… into agriculture crops; secondly, allelopathic plants could be planted in rotation with the 11………………; finally, naturally produced chemicals could be combined with 12…………………………… herbicides. However, agriculturalists are still 13…………………………. about allelopathic plants that may have negative effects on plants which are not the intended target and the chemicals could remain in the ground for a(n) 14…………………., even after the plants themselves have died.

Mutual Harm Reading Answers with Explanations

1 Answer: v

Question type: Matching Headings

Answer location: Paragraph B

Answer explanation: The second paragraph begins with the line – “The phenomenon by which an organism produces one or more chemicals that influence the growth, survival and reproduction of other organisms is called allelopathy.” and continues with more information on the word ‘allelopathy’, its meanings and related concepts. Hence, the answer is v (What is allelopathy?).

2 Answer: vii

Question type: Matching Headings

Answer location: Paragraph C

Answer explanation: In the third paragraph, it is noted that “It can affect where certain species of plant grow, the fertility of competitor plants, the natural change of plant communities over time, which plant species are able to dominate a particular area, and the diversity of plants in an area…It was also realised that some species could have beneficial effects on agricultural crop plants and the possible application of allelopathy became the subject of research.”. It can be pointed out that this paragraph discusses the effects of allelopathy on other species, plant communities, diversity of plants along with its possible benefits on agricultural plants. Hence, the answer is vii (The effects of allelopathy and realization of its possible uses).

3 Answer: ix

Question type: Matching Headings

Answer location: Paragraph D

Answer explanation: In the mentioned paragraph, it is stated that “a small fast-growing tree found in Central America, sometimes called ‘miracle tree’, contains a poison that slows the growth of other trees but does not affect its own seeds… box elder – another tree – stimulates the growth of bluestem grass, which is tall prairie grass found in the mid-western United States. Many weeds may use allelopathy to become ecologically successful…”. From the given reference, it can be said that the fourth paragraph deals with examples of specific allelopathic plants and their benefits. Hence, the answer is ix (Specific examples of allelopathic plants).

4 Answer: viii

Question type: Matching Headings

Answer location: Paragraph E

Answer explanation: In the introductory line of the specified paragraph, it is reported that “There may be at least three applications of allelopathy to agriculture.”. It can be concluded that the fifth paragraph explains the three benefits of allelopathic chemicals in farming (agriculture) that are yet known to the scientists through research. Hence, the answer is viii (How could we use allelopathic chemicals in farming?).

5 Answer: iv

Question type: Matching Headings

Answer location: Paragraph F

Answer explanation: In the concluding paragraph, it is stated that “Because the effects of allelopathic chemicals are not yet fully known, agriculture scientists will need to continue to study the biological war between plants.”. Here, it is clear that even though scientists have looked into the various benefits and possible usage of the allelopathic plants and chemicals, a lot is still unknown. As a result, we cannot use allelopathic chemicals now. Hence, the answer is iv (Why we cannot use allelopathic chemicals at present).

6 Answer: C

Question type: Multiple-Choice Question

Answer location: Paragraph B, line 1

Answer explanation: In the indicated location, it is given that “The phenomenon by which an organism produces one or more chemicals that influence the growth, survival and reproduction of other organisms is called allelopathy.”. The quoted line points out that allelopathy is the process by which the chemicals produced by an organism (plants) affect another organism (plant). Hence, the answer is C (the effects of chemicals produced by a plant on another plant).

7 Answer: C

Question type: Multiple-Choice Question

Answer location: Paragraph C, line 3

Answer explanation: In the specified lines, it is given that “It can affect… the diversity of plants in an area. Plants can release allelopathic chemicals in several ways: their roots can release chemicals directly into the soil , and their bark and leaves can release chemicals into the soil as they rot…interestingly, the occurrence of weed – free areas.”. In other words, allelopathy can affect the diversity of plants in an area, how certain species of plants change the nature of the soil where they grow by releasing chemicals into the soil and the negative effects of weeds which keep an area weed-free. The only thing that allelopathy does not affect or decide is the nutrients present in the soil. Hence, the answer is C (the nutrients present in the soil.).

8 Answer: A

Question type: Multiple-Choice Question

Answer location: Paragraph D, line 2

Answer explanation: In the fourth paragraph, it is specified that “Agricultural scientists are exploring the use of allelochemicals to regulate growth and to act as natural herbicides, thereby promoting sustainable agriculture by using these natural chemicals as an alternative to man-made chemicals.”. From this reference, it can be concluded that scientists are interested in exploring the use of the allelochemicals and being able to exploit them in promoting sustainable farming by replacing man-made chemicals with these natural chemicals. Hence, the answer is A (being able to exploit allelopathy in sustainable farming.).

9 Answer: A

Question type: Multiple-Choice Question

Answer location: Paragraph D, line 3-line 6

Answer explanation: In the cited lines, it is stated that “For example, a small fast-growing tree found in Central America, sometimes called ‘miracle tree’, contains a poison that slows the growth of other trees but does not affect its own seeds. Chemicals produced by this tree have been shown to improve the production of rice. Similarly, box elder – another tree – stimulates the growth of bluestem grass, which is tall prairie grass found in the mid-western United States. Many weeds may use allelopathy to become ecologically successful; a study in China found that 25 out of 33 highly poisonous weeds had significant allelopathic properties.”. Based on these statements, it can be commented that the passage includes examples of trees that makes a type of grass (bluestem grass) grow better (box elder), one which makes rice more productive as well as affects the growth of other trees (miracle tree). However, there is no mention of a tree that is highly poisonous to weeds; rather there is a reference to weeds that use allelopathy. Hence, the answer is A (a tree which is highly poisonous to weeds).

10 Answer: bred