Scientists in the US have created a new strain of mosquito that’s resistant to malaria, meaning it can’t then pass the disease onto humans. But their release into the wild is several years away.
Scientists say this is a key step on a long journey towards fighting the disease with genetically modified mosquitoes. The researchers used a single genetic tweak to interfere with the production of a molecule in the insect’s gut. Previous studies have attempted a similar approach, but this is the first time that scientists have completely blocked the development of the malaria parasite inside the mosquito. This rendered the insect unable to spread the disease. The ultimate aim is to release these malaria-resistant mosquitoes into the wild, but scientists will first need to work on more genetic trickery to give their insects a competitive advantage over their disease-spreading counterparts.
Scientists in the US have created a new strain of mosquito that’s resistant to malaria, meaning it can’t then pass the disease onto humans. But their release into the wild is several years away.
Scientists say this is a key step on a long journey towards fighting the disease with genetically modified mosquitoes. The researchers used a single genetic tweak to interfere with the production of a molecule in the insect’s gut. Previous studies have attempted a similar approach, but this is the first time that scientists have completely blocked the development of the malaria parasite inside the mosquito. This rendered the insect unable to spread the disease. The ultimate aim is to release these malaria-resistant mosquitoes into the wild, but scientists will first need to work on more genetic trickery to give their insects a competitive advantage over their disease-spreading counterparts.
Scientists have created a tomato that can grow on salty water. The plant is the first crop of its kind ever produced in the world.
Its significance can not be overestimated (高估). The new technology can help mankind solve the problem of feeding its ever-expanding population. It is estimated that by 2025 the world population will amount to more than 9 billion, an increase of 3 billion over 2000. Each day 240,000 more people are born, ready to be fed like the rest of us. Unfortunately, not all the land on Earth can be used to grow crops for humans. About 24.7 million acres of the problem is irrigation (灌溉). When farmers water their crops, salts in the water also enter the soil. Over time, salts such as sodium (钠) and calcium (钙) build up to such a point that they severely harm the growth of crops. Salts destroy most plants’ ability to draw up water through their roots.
But, the new variety of tomato produced by American and Canadian scientists can store salts i
A. importance
B. quality
C. price
D. quantity
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