9. Ways plants defend themselves from insects

리스닝 듣기


Using points and examples from the talk, explain some ways plants defend themselves from insects presented by the professor.


말하기 준비 시간: 30초
말하기 녹음 시간: 1분


리스닝 스크립트

We all know that insects like to eat plants. But some plants have been able to develop ways to protect themselves from insects. Today, I’m gonna talk about some ways plants defend themselves.
Now, some plants have physical features that prevent insects from landing on them, like the passion plant for example, its leaves have little spiky hairs all over them. They’re like spikes sticking out the plant that are so numerous and dense that they prevent insects from landing on the leaves. Basically, there’s just no room for the insects to land. And since insects can’t land on the leaves, they can’t eat them. So the little hairs serve as a physical feature that helps protect the passion plant from insects.
All right, but other plants protect themselves using chemical defenses like the potato plant. The potato plant’s able to release a chemical throughout its leaf system whenever an insect attacks it and starts eating leaf. So, say an insect starts eating a potato plant’s leaf. That will cause the plant to react by releasing a chemical throughout its leaf system. The insect swallows this chemical as it eats. And this chemical discourages the insect from wanting to eat any more of the plant. How? Well, the substance makes the insect feel full like it’s already had enough to eat. The insect no longer feels hungry so it stops eating the plant. So by emitting this chemical, the potato plant protects itself from insects.


30점을 위한 해설

The professor explains some ways for plants to defend themselves. (식물들이 자신을 보호하는 몇가지 방식에 대해 설명함)
First, some plants develop physical features to keep insects from landing on them. (첫째, 어떤 식물은 곤충들이 앉지 못하도록 하는 물리적인 특징을 발전시켰음)
For example, passion plants have little spiky hairs on their leaves. (예를 들어, 패션 식물은 잎에 작은 뾰족한 털을 가지고 있음)
The hairs are so numerous and dense, that insects do not have space to land on the plants, preventing them from eating plants. (그 털은 아주 많고 빽빽해서 곤충들이 식물위에 앉을 공간을 없애 결국 곤충이 그 식물을 먹을 수 없게 함)
Another feature is having chemical defenses. (또 다른 특징은 화학적인 방어임)
The potato plant, for example, is able to release a chemical when an insect attacks it. (예를 들어, 포테이토 식물은 곤충이 공격할 때 화학 물질을 방출함)
When the insect shallows this chemical, the chemical makes the insect feel like it has had enough food already and is full. (곤충이 이 화학 물질을 삼키면, 그 곤충은 이미 충분한 음식을 먹었고 배부르다고 느끼게 됨)
With this form of defense, the plant can protect itself from being a source of food for the insect. (즉, 곤충은 더 이상 먹고 싶어하지 않으며 이런 방식으로 식물은 곤충으로부터 자신을 보호할 수 있음)


샘플 답안

In the lecture, the professor outlines various defense mechanisms employed by plants to protect themselves from predators.

One such defense mechanism involves the development of physical features aimed at deterring insects from landing on the plants. For instance, passion plants exhibit tiny spiky hairs on their leaves, which are densely distributed to create an inhospitable surface for insects to land on. The abundance and density of these hairs effectively prevent insects from accessing and consuming the plant, thereby serving as a physical barrier against herbivory.

Another defense strategy utilized by plants involves the production of chemical defenses. For example, when a potato plant is attacked by insects, it releases a chemical compound that induces a sensation of satiety in the insect upon ingestion. As a result, the insect perceives itself as having consumed sufficient food and ceases further feeding on the plant. By employing chemical defenses, the potato plant effectively deters herbivores and safeguards itself from being consumed as a food source.