Question: Using the examples from the lecture, explain the professor's main point about Batesian mimicry.
🎧 听力讲座
Today, we're going to discuss a fascinating concept in biology called 'mimicry,' specifically when a harmless species evolves to look like a dangerous one to avoid predators. This is known as Batesian mimicry. The key point is that mimicry isn't just about looking similar; it's about survival through deception. Let me give you two examples. First, consider the scarlet king snake. It has bright red, yellow, and black bands, very similar to the deadly coral snake. Predators avoid the coral snake because its venom is lethal, so they also avoid the king snake, even though it's harmless. Second, think about the hoverfly. It has black and yellow stripes, resembling a wasp. Wasps can sting, so birds and other insects steer clear of hoverflies, which actually have no stinger. In both cases, the mimic gains protection without having the actual defense mechanism. This illustrates how natural selection favors those that look dangerous, even if they aren't.
📝 参考答案
托福口语 Task 4 评分标准
内容准确性(Content Accuracy):是否准确复述教授的主要观点
信息完整性(Information Completeness):讲座中的例子和关键细节是否完整
语言运用(Language Use):语法、词汇、表达准确性
表达(Delivery):流利度和清晰度
总分30分,原始分0-4分,最终换算为30分制。
答题技巧
听讲座时快速记笔记,抓住主要观点和两个例子
用20秒准备时间组织回答结构
回答时先点明教授的主要观点,再用例子解释
使用模板句式:"The professor explains... For example..."
控制在60秒内完成回答
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