首页
登录
职称英语
Listen to part of a lecture in a zoology class.Professor:As you know from the
Listen to part of a lecture in a zoology class.Professor:As you know from the
游客
2024-01-03
83
管理
问题
Listen to part of a lecture in a zoology class.
Professor:
As you know from the textbook, mimicry isn’t limited to insects, but it’s most common among them, and by mimicry I’m referring to the likeness between two insects that aren’t closely related but look very much alike. The insects that engage in mimicry are usually very brightly colored. One of the insects, the one that’s characterized by an unpleasant taste, a bad smell, a sting or bite, that insect is called the model. The mimic looks like the model but doesn’t share the characteristic that protects the model from predators. But, of course, the predators associate the color pattern or some other trait with the unpleasant characteristic and leave both insects alone.
Henry Bates was one of the first naturalists who noticed that some butterflies that closely resembled each other were actually unrelated, so mimicry in which one species copies another is called Batesian mimicry. I have some lab specimens of a few common mimics in the cases here in the front of the room, and I want you to have a chance to look at them before the end of the class. There’s a day flying moth with brown and white and yellow markings. And this moth is the model because it has a very unpleasant taste and tends to be avoided by moth eaters. But you’ll notice that the swallowtail butterfly mounted beside it has very similar coloration, and actually the swallowtail doesn’t have the unpleasant taste at all. Another example is the monarch butterfly, which is probably more familiar to you since they pass through this area when they’re migrating. But you may not know that they have a very nasty taste because I seriously doubt that any of you have eaten one. But for the predators who do eat butterflies, this orange and black pattern on the monarch is a warning signal not to sample it. So, the viceroy butterfly here is a mimic. Same type of coloring but no nasty taste. Nevertheless, the viceroy isn’t bothered by predators either, because it’s mistaken for the monarch. So how does a predator know that the day flying moth and the monarch aren’t good to eat? Well, a bird only has to eat one to start avoiding them all—models and mimics.
A stinging bumblebee is another model insect. The sting is painful and occasionally even fatal for predators. So there are a large number of mimics. For example, there’s a beetle that mimics bumblebees by beating its wings to make noise, and the astonishing thing is that it’s able to do this at the same rate as the bumblebee so exactly the same buzzing sound is created. I don’t have a specimen of that beetle, but I do have a specimen of the hoverfly, which is a mimic of the honeybee, and it makes a similar buzzing sound, too. When you compare the bee with the fly, you’ll notice that the honeybee has two sets of wings, and the hoverfly has only one set of wings, but as you can imagine, the noise and the more or less similar body and color will keep most predators from approaching closely enough to count the wings.
Some insects without stingers have body parts that mimic the sharp stinger of wasps or bees. Although the hawk moth is harmless, it has a bundle of hairs that protrudes from the rear of its body. The actual purpose of these hairs is to spread scent, but to predators, the bundle mimics a stinger closely enough to keep them away, especially if the hawk moth is moving in a threatening way as if it were about to sting. There’s a hawk moth here in the case, and to me at least, it doesn’t look that much like the wasp mounted beside it, but remember when you’re looking at a specimen, it’s stationary, and in nature the movement is also part of the mimicry.
Oh, here’s a specimen of an ant, and this is interesting. Another naturalist, Fritz Muller, hypothesized that similarity among a large number of species could help protect all of them. Here’s what he meant. After a few battles with a stinging or biting ant, especially when the entire colony comes to the aid of the ant being attacked, a predator will learn to avoid ants, even those that don’t sting or bite, because they all look alike and the predator associates the bad experience with the group. And by extension, the predator will also avoid insects that mimic ants, like harmless beetles and spiders.
Look at this.
I have a drawing of a specimen of a stinging ant beside a specimen of a brownish spider and the front legs of the spider are mounted so they look more like antennae because that’s just what the spider does to mimic an ant. That way it appears to have six legs like an ant instead of eight like a spider.
Okay, we have about ten minutes left, and I want you to take this opportunity to look at the specimen cases here in the front of the room. I’ll be available for questions if you have them. How about forming two lines on either side of the cases so more of you can see at the same time? [br] E A biting ant
Listen to part of a lecture in a zoology class.
Professor:
As you know from the textbook, mimicry isn’t limited to insects, but it’s most common among them, and by mimicry I’m referring to the likeness between two insects that aren’t closely related but look very much alike. The insects that engage in mimicry are usually very brightly colored. One of the insects, the one that’s characterized by an unpleasant taste, a bad smell, a sting or bite, that insect is called the model. The mimic looks like the model but doesn’t share the characteristic that protects the model from predators. But, of course, the predators associate the color pattern or some other trait with the unpleasant characteristic and leave both insects alone.
Henry Bates was one of the first naturalists who noticed that some butterflies that closely resembled each other were actually unrelated, so mimicry in which one species copies another is called Batesian mimicry. I have some lab specimens of a few common mimics in the cases here in the front of the room, and I want you to have a chance to look at them before the end of the class. There’s a day flying moth with brown and white and yellow markings. And this moth is the model because it has a very unpleasant taste and tends to be avoided by moth eaters. But you’ll notice that the swallowtail butterfly mounted beside it has very similar coloration, and actually the swallowtail doesn’t have the unpleasant taste at all. Another example is the monarch butterfly, which is probably more familiar to you since they pass through this area when they’re migrating. But you may not know that they have a very nasty taste because I seriously doubt that any of you have eaten one. But for the predators who do eat butterflies, this orange and black pattern on the monarch is a warning signal not to sample it. So, the viceroy butterfly here is a mimic. Same type of coloring but no nasty taste. Nevertheless, the viceroy isn’t bothered by predators either, because it’s mistaken for the monarch. So how does a predator know that the day flying moth and the monarch aren’t good to eat? Well, a bird only has to eat one to start avoiding them all—models and mimics.
A stinging bumblebee is another model insect. The sting is painful and occasionally even fatal for predators. So there are a large number of mimics. For example, there’s a beetle that mimics bumblebees by beating its wings to make noise, and the astonishing thing is that it’s able to do this at the same rate as the bumblebee so exactly the same buzzing sound is created. I don’t have a specimen of that beetle, but I do have a specimen of the hoverfly, which is a mimic of the honeybee, and it makes a similar buzzing sound, too. When you compare the bee with the fly, you’ll notice that the honeybee has two sets of wings, and the hoverfly has only one set of wings, but as you can imagine, the noise and the more or less similar body and color will keep most predators from approaching closely enough to count the wings.
Some insects without stingers have body parts that mimic the sharp stinger of wasps or bees. Although the hawk moth is harmless, it has a bundle of hairs that protrudes from the rear of its body. The actual purpose of these hairs is to spread scent, but to predators, the bundle mimics a stinger closely enough to keep them away, especially if the hawk moth is moving in a threatening way as if it were about to sting. There’s a hawk moth here in the case, and to me at least, it doesn’t look that much like the wasp mounted beside it, but remember when you’re looking at a specimen, it’s stationary, and in nature the movement is also part of the mimicry.
Oh, here’s a specimen of an ant, and this is interesting. Another naturalist, Fritz Muller, hypothesized that similarity among a large number of species could help protect all of them. Here’s what he meant. After a few battles with a stinging or biting ant, especially when the entire colony comes to the aid of the ant being attacked, a predator will learn to avoid ants, even those that don’t sting or bite, because they all look alike and the predator associates the bad experience with the group. And by extension, the predator will also avoid insects that mimic ants, like harmless beetles and spiders.
Look at this.
I have a drawing of a specimen of a stinging ant beside a specimen of a brownish spider and the front legs of the spider are mounted so they look more like antennae because that’s just what the spider does to mimic an ant. That way it appears to have six legs like an ant instead of eight like a spider.
Okay, we have about ten minutes left, and I want you to take this opportunity to look at the specimen cases here in the front of the room. I’ll be available for questions if you have them. How about forming two lines on either side of the cases so more of you can see at the same time?
选项
A、Mimic
B、Model
答案
B
解析
转载请注明原文地址:https://www.tihaiku.com/zcyy/3329730.html
相关试题推荐
[img]2012q1/ct_etoefm_etoefspeakc_1287_20121[/img]Nowlistentopartofal
Somestudentslearnbetterbyreading.Otherslearnmorefromlisteningtoatea
Biology[img]2012q1/ct_etoefm_etoeflistz_0555_20121[/img][br]Listenagaintopa
[img]2012q1/ct_etoefm_etoefspeakc_1403_20121[/img]Nowlistentoashortcon
"FaxMachines"[img]2012q1/ct_etoefm_etoefspeakc_1738_20121[/img]Nowlisten
[img]2012q1/ct_etoefm_etoeflistz_0327_20121[/img][br]Listenagaintopartoft
[img]2012q1/ct_etoefm_etoeflistz_0321_20121[/img][br]Listenagaintopartoft
[img]2012q1/ct_etoefm_etoefspeaka_1180_20121[/img]Listenforaquestionthat
[img]2012q1/ct_etoefm_etoefspeaka_1179_20121[/img]Listenforaquestionabou
NarratorListentopartofaconversationbetweentwostudents.No
随机试题
Someyearsago,thumping,jumpingnoisesroutinelyissuedfromtheapartment
WhenIfinallysecuredasmallpartinatelevisionplaymymotherwasasproud
Wal-Mart[A]Wal-Martismorethanjusttheworld’sl
[originaltext]Listentopartofatalkinaclassonearlychildhoodeducat
是不以盈利为目的,向有需要的人士提供福利服务为宗旨。()A.社会福利服务机构
雄激素转化为雌激素需要下列哪种酶类:()A.3β-羟甾脱氢酶 B.
赵先生46岁,身高170Cm,体重80kg,证券公司部门经理,在某健康管理中心要
伤寒病儿入院时常规培养A.血培养 B.粪便培养 C.尿培养 D.胆汁培养
替代品价格是决定某商品需求的因素之一,替代品价格与商品需求的关系是( )。A.
下列()建筑可采用剪刀楼梯间。A.高层公共建筑的疏散楼梯,当分散设置确有困难且
最新回复
(
0
)