What is the lecture mainly about? [br] According to the professor, what did the

游客2024-01-02  6

问题 What is the lecture mainly about? [br] According to the professor, what did the researchers learn about proteins produced from plant seeds?
Listen to part of a lecture in a biology class.
    Professor:
    I’m sure most of you know that we’ve been able to extract certain compounds from plants for use in medicine. Eh, compounds like proteins from some plants can be used in medicines as antibodies in vaccines. And we can even cause some plants to produce certain proteins by incorporating DNA into the plant cells, usually in the leaves. We then extract the proteins to use as antibodies. However, we’ve never been able to produce enough protein to make the process worthwhile. It hasn’t been practical until now.
    Now it appears that it’s possible to get a large amount of usable protein from plants. Some researchers have recently succeeded in doing this by using plant seeds to produce these proteins rather than leaves or the other parts of the plant.
    Now there are a number of advantages to get protein from plant seeds to produce antibodies. But we have to be sure that these proteins are just as effective as human proteins. And so far the researchers show that antibodies produced from plant seeds protein are effective in humans, which is great. Because typically, antibodies for vaccines and medicines too are produced from micro-organisms like yeasts or bacteria, and it’s a rather complicated process.
    OK, so what makes plant seeds good production units? Well, for one thing, there are lots of them, right? One plant can produce a lot of seeds and then there is the issue of storage. Seeds can be stored for long periods of time and the protein retains its effectiveness.
    Now that’s not true with other parts of the plant. Leaves for instance, you can’t store them very long, which means you have to get that protein out right away as soon as it’s produced. But using plant seeds as production units allows you to isolate the protein whenever you need it, and you can transport seeds all over the world, even the places where refrigeration might be a problem, not so for yeasts and bacteria, but with seeds, it seems quite possible that we’ll be able to supply vaccine to places that need them. Whereas before this, transporting and preserving these products after a long distance simply wasn’t feasible. And another major benefit of extracting plant proteins for medical use is cost-effectiveness. Unlike the production of proteins for medicinal purpose using yeasts or bacteria like insulin which is a vital protein used in medications, extracting protein from seeds doesn’t require high-tech production labs with all kinds of equipment, and since refrigeration is not crucial for maintenance or transport, it’s just much less expensive to store and maintain plant seeds than other sources of protein. We estimate the total production cost to be 10 to 100 times lower.

选项 A、They produce antibodies that are effective in humans.
B、They are difficult to extract.
C、They are more suitable for medicinal use than antibodies produced from bacteria and yeasts.
D、They do not survive as long as proteins produced from leaves.

答案 A

解析 题目询问研究人员从植物种子生产的蛋白质中了解到什么。根据教授说的“研究人员证明了植物种子蛋白产生的抗体对人体是有效的”,可知A项正确。B项“难以提取”,讲座最后提到,从植物种子中提取蛋白质不需要配备高端仪器的生产试验室,故排除B项。C项“比起细菌和酵母生产的蛋白质,植物种子生产的蛋白质更加适用于医学用途”没有依据。D项“它们没有树叶生产的蛋白质存活的时间长”,录音没有对比二者生产出来的蛋白质的存活时间,仅提到了植物种子的蛋白质提取时间比叶子的蛋白质提取时间长,故不选D项。
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