1 . Animals can adapt quickly to survive unfavorable environmental conditions. Evidence is mounting to show that plants can, too. A paper published in the journal Trends in Plant Science details how plants are rapidly adapting to the effects of climate change, and how they are passing down these adaptations to their offspring(后代).
Plants are facing more environmental stresses than ever. For example, climate change is making winters shorter in many locations, and plants are responding. “Many plants require a minimum period of cold in order to set up their environmental clock to define their flowering time,” says Martinelli, a plant geneticist at the University of Florence. “As cold seasons shorten, plants have adapted to require shorter periods of cold to delay flowering. These mechanisms allow plants to avoid flowering in periods when they have fewer opportunities to reproduce.”
Because plants don’t have neural(神经的) networks, their memory is based entirely on cellular(细胞的),molecular(分子的),and biochemical networks. These networks make up what the researchers call somatic memory(体细胞记忆). “It allows plants to recognize the occurrence of a previous environmental condition and to react accordingly,” says Martinelli.
These somatic memories can then be passed to the plants’ offspring via epigenetics(表现遗传). “Several examples demonstrate the existence of molecular mechanisms modulating plant memory to environmental stresses and affecting the adaptation of offspring to these stresses,” says Martinelli.
Going forward, Martinelli hopes to understand even more about the genes that are being passed down. “We are particularly interested in decoding the epigenetic alphabet without changes in DNA sequence(序列),”he says. “This is especially important when we consider the rapid climate change, we observe today that every living organism, including plants, needs to quickly adapt to survive.”
1. What adaptations have plants made to shortened cold seasons?A.They have shortened their flowering time. |
B.They have got more chances to reproduce. |
C.They have avoided flowering in cold seasons. |
D.They have adjusted their environmental clock. |
A.It is entirely based on neural networks. |
B.It can help the plants’ offspring to survive. |
C.It can help relieve environmental stresses. |
D.It disturbs the plants’ biochemical networks. |
A.Adjusting. | B.Treasuring. |
C.Recording. | D.Sharing. |
A.Plants are smart about flowering time |
B.Plants can also adapt to climate change |
C.Environmental stresses challenge plants |
D.Mysteries of plant genes are to be unfolded |
2 . At first, the grains of rice that Ingo Potrykus held in his fingers did not seem at all
For more than a decade Potrykus had
At that point, he tackled an even greater challenge. The golden grains
The debate began the moment genetically engineered crops (GM crops) were first sold in the 1990s, and it has
The hostility is
The benefits did seem small
Many people
A.typical | B.special | C.local | D.white |
A.dreamed of | B.come in handy | C.been reminded of | D.broken up |
A.attempt at | B.effort to | C.resistance to | D.majority of |
A.But | B.And | C.While | D.Since |
A.surprise | B.obstacle | C.norm | D.opposition |
A.achieved | B.stressed | C.overlooked | D.contained |
A.was caught in | B.was alive with | C.be conscious of | D.was honored by |
A.announced | B.maintained | C.escalated | D.applied |
A.brilliant | B.understandable | C.discharged | D.rewarding |
A.introduced | B.reminded | C.respected | D.overlooked |
A.toss and turn | B.give and take | C.produce and sell | D.demand and supply |
A.until | B.after | C.although | D.when |
A.feature | B.mark | C.build | D.benefit |
A.worried about | B.ashamed of | C.filled with | D.admired for |
A.terror | B.misery | C.starvation | D.crisis |
3 . Scientists have been experimenting with playing sounds to plants since at least the 1960s, during which time they have been exposed to everything from Beethoven to Michael Jackson. Over the years, evidence that this sort of thing can have an effect has been growing. One paper, published in 2018, claimed that an Asian shrub known as the telegraph plant grew substantially larger leaves when exposed to 56 days of Buddhist music — but not if it was exposed to Western pop music or silence. Another, published last year, found that marigolds and sage plants exposed to the noise of traffic from a busy motorway suffered growth difficulty.
Plants have been evolving (进化) alongside the insects that eat them for hundreds of millions of years. With that in mind, Heidi Appel, a botanist now at the University of Houston, and Reginald Cocroft, a biologist at the University of Missouri, wondered if plants might be sensitive to the sounds made by the animals with which they most often interact. They recorded the vibrations made by certain species of caterpillars (毛毛虫) as they chewed on leaves. These vibrations are not powerful enough to produce sound waves in the air. But they are able to travel across leaves and branches, and even to neighbouring plants if their leaves touch.
They then exposed tobacco plant — the plant biologist’s version of the laboratory mouse — to the recorded vibrations while no caterpillars were actually present. Later, they put real caterpillars on the plants to see if exposure had led them to prepare for an insect attack. The results were striking. Leaves that had been exposed had significantly higher levels of defensive chemicals, making them much harder for the caterpillars to eat. Leaves that had not been exposed to vibrations showed no such response. Other sorts of vibration — caused by the wind, for instance, or other insects that do not eat leaves — had no effect.
“Now speakers with the right audio files are more often being used to warn crops to act when insects are detected but not yet widespread,” says Dr. Cocroft. “Unlike chemical pesticides, sound waves leave no dangerous chemicals.”
1. What can we learn about plants from the first paragraph?A.They may enjoy Western music. | B.They can’t stand Buddhist music. |
C.They can react to different sounds. | D.They can make different sounds. |
A.Plants can make a cry for help. | B.Plants evolve alongside insects. |
C.Plants are sensitive to the sounds. | D.Plants have been studied for years. |
A.They can recongnize harmful vibrations. | B.They look like laboratory mice. |
C.They can threaten the caterpillars. | D.They can release poisonous chemicals. |
A.Disadvantages of chemical pesticides. | B.Application of the experimental results. |
C.Interaction between plants and insects. | D.Warning system of widespread insects. |
4 . “A beautiful field of flowers can be a rather noisy place. It’s just that we can’t hear the sounds.” Scientists at Tel Aviv University have conducted a six-year experiment, proving that plants make noise in certain stressful situations.
Plants produce a high frequency (频率) clicking sound, and when short of water, or damaged, the clicks become far more regular. They also made different sounds, depending on whether they were thirsty or injured. “Each plant and each type of stress is related to a specific sound,” said Professor Lilach Hadany, who led the research study.
Focusing particularly on tomatoes, wheat and corn, the plants were placed in a soundproof (隔音的) room and recorded by microphones. Some plants were starved of water, others cut, and a control group was left undamaged. The researchers used an algorithm (算法) to separate the noises, successfully telling the difference between the sounds depending on whether they were dry or cut. The algorithm did this in a greenhouse setting which included far more surrounding sounds, but it was still able to recognize the particular cries for help of the plants.
On average, the human ear can hear sounds up to around 20kHz, while the sounds produced by plants are in the 40-80kHz region, far beyond our hearing. “The sounds made by plants can’t be heard by humans but can probably be heard by various animals, such as bats, mice and insects,” Hadany tells us. Though this has yet to be proven, it’s possible that these creatures use this information to choose which plants to eat.
A study led by Reda Hassanien of China Agricultural University in Beijing years ago, also proved that plants reacted to sound waves, with some plants greatly increasing their yield. While evidence shows that plants can react to sounds, there’s no evidence today that they can actually hear them.
1. What can we know from the six-year experiment?A.Plants of different types make the sound of the same frequency. |
B.Plants produce more regular sound in certain stressful situations. |
C.Plants make sounds with a much lower frequency when stressed. |
D.Plants make the sound of the same frequency whatever the situation. |
A.To record the sounds. | B.To control the sounds. |
C.To produce the sounds. | D.To identify the sounds. |
A.Plants can hear each other’s cry for help. |
B.Animals can hear the sounds made by plants. |
C.Plants can make sounds and respond to sound waves. |
D.Animals decide what to eat based on the sounds plants make. |
A.Sounds That We Can’t Hear |
B.Beautiful Songs from Plants |
C.Plants React to Different Types of Stress |
D.Plants Talk, Especially When Stressed |
5 . It turns out our plants are just like us in some ways. We turn to medicines to relieve a minor flu or headache, and plants too have their ways of self-medicating. They protect themselves from environmental hazards like insects, drought and heat by producing salicylic acid (水杨酸). It is responsible for the anti-inflammatory action of aspirin, a drug which has been used by humans for centuries to counter pain and inflammation.
Researchers have found that plants’ salicylic acid, which is produced in chloroplasts (叶绿体), is usually generated in response to the stress caused by climate change. “It’s like plants use a painkiller for aches and pains, just like we do,” said plant biologist Wilhelmina van de ven from the University of California, River-side (U. C. R)
“We’d like to be able to use the finding to improve crop resistance (作物抗性),” said U. C. R.plant geneticist Jin-Zheng Wang. “That will be crucial for the food supply in our increasingly hot, bright world.”
Human skin produces ROS (Reactive oxygen species) (活性氧) in the absence of sunscreen. This causes freckles and burns. Similarly, environmental stresses result in the formation of ROS in plants which, at high levels, can cause death.
At low levels, however, ROS serves an essential function in plant cells. “ROS is a double-edged sword,” said Wang. “At non-lethal levels, ROS are like an emergency call to action, enabling the production of protective hormones ( 激素) such as salicylic acid.” The acid then acts to protect the plants’ chloroplasts, known to be the site of photosynthesis.
“With climate change, things like salicylic acid: helping plants stand up to stresses have become more common. So, being able to increase plants’ ability to produce it represents a step forward in challenging the impacts of climate change on everyday life,” said Katayoon Dehesh, UCR professor of molecular biochemistry.
“Those impacts go beyond our food. Plants being in trouble are a sign of what the future holds for us,” she continued. “Plants clean our air by removing the carbon dioxide from it while also offering us shade, and providing habitats for numerous animals. For humankind, the benefits of boosting plants’ ability to survive are becoming increasingly essential.”
1. What is the main function of salicylic acid in plants?A.To secure plants. | B.To produce chloroplasts. |
C.To relieve pain and inflammation. | D.To generate hormones. |
A.Lack of sunscreen. | B.Chloroplastic acid. |
C.Environmental stresses. | D.Use of Photosynthesis. |
A.To explore the history and significance of aspirin in human medicine. |
B.To invent a device that can make plants do self-medicating. |
C.To compare the differences between plants and humans in self-medicating. |
D.To improve crop resistance by increasing plants’ ability to produce salicylic acid. |
A.Plants can be improved to resist environmental hazards. |
B.Plants produce their own aspirin to cope with stress. |
C.Plants and humans share some common features and needs. |
D.Plants contribute to the well-being of humans and animals. |
6 . Bred to be more sweeter, today’s cherries, bananas and apples taste different than they used — to but not necessarily better. Among fruit farmers, the word “quality” is now routinely used as a standard for “high in sugar”, though firmness, color and size are also considerations. In a recent study about ways to enhance the sweetness of fruit using “molecular (分子的) approaches”, a group of plant scientists wrote that, in general, the sugar content of many fruits are now higher than before owing to continuous selection and breeding. Modern apple varieties, the scientists stressed, were on average sweeter than older ones.
The sweetness of fruit depends not just on how it is bred but also on growing conditions, yield and harvest. The lead researcher, Sugiura, said, “If you could taste an apple harvested 30 years ago, you would feel the difference.” He believed that modern apples are picked so early that even if they are bred for sweetness, they often don’t develop their full character. The fragrance (香味) never develops in fruit that is harvested too early.
Jim Cooper, an apple farmer in England, is regretful to admit the fact that many people will never taste the “strawberry hint” in a really ripe Pearmain, a type of heritage apple. In a way, the rise of consistently sweeter fruit in our lifetimes has been a victory of plant breeding. After all, it’s a rare person who would seek out bitter grapes if they could have sweet ones instead.
But the sweetness of modern fruit is not without its problems, especially for people with diabetes (糖尿病), who have to reduce their intake of higher-sugar fruits. Fruit that is bred sweeter also tends to be lower in the chemicals that make it healthy. Considering health, maybe the real problem with modern fruit is that it has become yet another sweet thing in a world with sugar. Even grapefruits, which used to be quite bitter, are sometimes now as sweet as oranges. If you’ve never tasted a sour cherry, how can you fully appreciate a sweet one?
1. In what aspect is many fruits different from before?A.Sugar content. | B.Soft skin. | C.Bright color. | D.High yield. |
A.They are bred too early. | B.They taste so sweet. |
C.They are losing a good flavor. | D.They need a higher yield. |
A.Favorable. | B.Critical. | C.Ambiguous. | D.Indifferent. |
A.It’s a wise choice to breed fruits for sweetness. |
B.Breeding sweet fruits improves the quality of fruits. |
C.Some fruits like grapes and cherries taste the same. |
D.The sweetness of fruits will cause health issues. |
7 . As I look out of the window, an icy wind blows oak leaves across the yard. The stove in the living room has been maintaining a temperature that keeps my family comfortable through this winter’s temperature swings.
Plants naturally lose water from leaves through a process called transpiration (蒸腾作用). As a result, the plant’s roots take up water from the soil to replace what was lost.
Since light levels are lower in winter and plant growth slows, houseplants typically have little need for fertilizer during winter months.
A.It is not recommended to fertilize. |
B.Eventually, the soil will become dry. |
C.Wait until late winter/early spring to fertilize. |
D.It may change the amount of light reaching your plant. |
E.There are two additional considerations for where to place houseplants. |
F.You should water when the soil feels dry to the touch one-half-inch deep. |
G.While this may be good for the family, it may not be so for my houseplants. |
With high yield and superior quality, Chinese hybrid rice varieties have been introduced around the world,
In the past 40 years, Chinese scientists
Yuan Longping,
It
9 . The world loves a cup of tea. It only takes a few grams to make a cup of tea and millions of tons of tea are consumed every year. Tea can be good for you because it contains some things that help lower cholesterol and reduce the risk of cardiovascular disease. Tea also contains caffeine(咖啡因), which improves not only mental alertness but can also increase anxiety and cause other problems.
What would be agreeable is a tea plant that provides all the taste and goodness but with little or none of caffeine. Chen Liang and Jin Jiqiang in the Tea Research Institute, Chinese Academy of Agricultural Sciences think they have found just such a plant, growing wild in a remote area in southern China’s Fujian Province. Known locally as hongyacha, the discovered plant grows only between 700 meters and 1,000 meters above sea level around a handful of Chinese villages. As they report in the Journal of Agricultural and Food Chemistry, not only is the tea plant naturally caffeine-free but it also contains a number of unique medicinal compounds that, the locals believe, offer considerable health benefits.
The researchers are now exploring methods to protect hongyacha in its natural habitat while further studies are carried out. It can take time—and sometimes it does not work—for new plant varieties to be bred for commercial use. A pair of naturally caffeine-free coffee plants were discovered in 2003, but little progress has been reported. Tea lovers will be watching hongyacha with interest. And others will wonder what else is out there.
1. What’s the disadvantage of drinking tea according to paragraph 1?A.It can make people hard to sleep. | B.It can make people feel anxious. |
C.It can get people addicted. | D.It can take people much time. |
A.It is nothing but just medicine. | B.It can only survive in greenhouses. |
C.It is a good pick for caffeine lovers. | D.It has a good taste and little caffeine. |
A.Its future location. | B.Its natural habitats. |
C.Its future market. | D.Its production process. |
A.A health magazine. | B.An advertising brochure. |
C.A travel guidebook. | D.A newspaper. |
10 . Recent research confirms what our farming ancestors have known for centuries about hedges (树篱). They conserve precious soil by acting as windbreaks and absorbing rainwater that would otherwise wash it from the fields. And hedges store carbon, putting them in the front line of our bi d to tackle the climate crisis.
However, hedges have had a tough time in the poor countryside, with farmers encouraged to tear them down in pursuit of maximum production and larger field s to accommodate ever-larger machinery. What’s more, some hedges have been ignored. If left to their own devices, they’ll eventually become a line of trees. Some hedges each year lose their structures and fail to fulfil the primary duty as a barrier. Around a half of the nation’s hedges have disappeared in the past century.
There are signs that “the tide is turning”. The search for net zero has aroused many organizations’ interest in the humble hedge’s role as a carbon sink. The Climate Change Committee is recommending a 40 percent increase in hedges: an additional 200,000 km. Such recommendations are starting to drive policy. Cash-pressed farmers will be encouraged to create new hedges and improve their management of existing ones under the new Environmental Land Management Schemes, which will replace many of the existing agricultural support payments in coming years. Meanwhile, initiatives such as Close the Gap, led by the Tree Council, is providing funding and support to plug the gaps in existing hedges with new planting. There’s even an app to help time-pressed farmers do a quick survey to spot where their hedges need some help.
This is a good time for hedges. Take some of the most pressing challenges facing the countryside, and indeed, the world as a whole — the climate crisis, soil erosion (侵蚀), insect attack and wider biodiversity loss — and hedges are part of the solution.
1. What does recent research show about hedges?A.They are unique landscapes in the rain. |
B.They act as dividing lines between fields. |
C.They have long been helpful to agriculture. |
D.They are frequently washed away from the fields. |
A.Their suffering. | B.Their production. |
C.Their duties. | D.Their structures. |
A.Puzzled. | B.Concerned. | C.Humble. | D.Indifferent. |
A.Hedges: Ancient Resources |
B.Hedges: Official Recommendations |
C.Restoring Hedges: Bringing Benefits to the Environment |
D.Researching Hedges: Originating from Farmers’ Request |