Day 1

P: OK. So far we’ve been studying interactions of populations in nature that belong to a category of negative. Um... we’ve discussed predators that feed on the prey, like wolf and rabbit, corn root worms that feed on the corn and so forth. This type of relationship is characterized by the fact that one organism actually harms the other. Today I want to begin talking about some positive interactions.

First of all, let’s look at mutualism and the classic mutualistic relationship.
A mutualistic relationship is when two organisms of different species “work together,” each benefiting from the relationship and do not harm each other. Some mutualisms are so close that interacting species actually can’t survive without each other. One good example of this is the mutualistic relationship between the yucca plant and yucca moth, which you read about in your textbook for today.

1. What is the lecture mainly about?

● A dependent relationship between a plant and an insect species
● How the relationship between the yucca plant and yucca moth is changing
● A type of mutualistic relationship involving more than two species
● Harmful relationship between various types of organisms

[유형] Main Idea Q

[해설]

― signal word 는 (today I want to begin talking about ~~) 하면서 general information(positive interaction) 을 준다. general information 뒤에 곧바로 specific information 이 뒤따른다.
― mutulalism의 정의를 내린 뒤의 (some mutualism~~) 은 구체적인 정보를 알리는 signal 이라고 할 수 있겠다.
― (Some mutualisms are so close ~~~~~. One good example ~~~, which you read about in your textbook for today.) 이 부분이 정확히 정답의 근거가 된다.

[정답] A

[오답분석]

― B는 (changing)때문에 답이 될 수 없다. relationship 이 변한다는 얘기는 언급하지 않는다
― C는 얼핏 볼 때, mutualistic relationship이라는 부분 때문에 정답으로 고를 수 있지만, (more than two) 때문에 답이 될 수 없다. more than two 는 3을 의미하기 때문이다.
― D는 맨 처음에 소거해야 할 answer choice 이다. harmful 은 지난 시간과 관련이 있다.