首页
登录
职称英语
Zoology Animal Defenses[img]2012q1/ct_etoefm_etoeflistz_0219_20121[/img] [br] Wh
Zoology Animal Defenses[img]2012q1/ct_etoefm_etoeflistz_0219_20121[/img] [br] Wh
游客
2024-01-04
32
管理
问题
Zoology Animal Defenses
[br] What topics does the professor mainly discuss? Click on two answers.
One of the most important relationships between different animal species is predation—the predator-prey interaction, in which a predator eats a prey. Predator species have several adaptations that help them catch prey species. Prey species have adaptations, too—physical and behavioral adaptations that enable them to elude predators and avoid being eaten. These defensive adaptations evolved in prey species through repeated encounters with predators over evolutionary time.
Some animal defenses are passive, such as hiding. Some defenses are active, such as escaping. Fleeing—running away—is the most direct anti-predator response, but it requires the animal to expend a lot of energy. A rabbit uses up a lot of energy running away from a lynx. Many animals avoid expending too much energy by escaping into a shelter.
Several prey species have some sort of vocalization—an alarm call—to announce the presence of a predator. The alarm call often triggers a behavioral defense called mobbing. During mobbing, the prey turns the tables and attacks the predator. For example, when a chickadee spots a threat—say, an owl—it calls out the alarm. The chickadee starts scolding the owl, sometimes actually striking it from behind. Birds of other species may fly in to investigate, and often participate in the mobbing. The other birds chase, dive-bomb, or surround the owl, usually vocalizing loudly. Their intent is to encourage the "enemy" to move on to another area.
Some animals rely on defensive coloration. A well-known example of defensive coloration is camouflage, which makes prey difficult to spot against a background of similar color. All a camouflaged animal has to do is remain still to avoid being seen. Thus, camouflage is probably the most effective passive defense. Incidentally, some predators also use camouflage, especially predators who lie in wait for prey and have to blend into their environment.
Moths that camouflage themselves to match a leaf stand a good chance of not being seen by moth-eating birds, unless, of course, the moths become so populous that a bird is likely to come across one by accident. Once the bird learns the moth’s identity, it has a search image for it, and the moth’s disguise is useless. Looking like a leaf is then no advantage because the bird will start pecking at leaves in the hope that they are moths, and it will keep doing it as long as a sufficient number do turn out to be moths.
Another animal defense is the use of chemical weapons. We’re all familiar with the chemical weapon of the skunk. Some animals—like poisonous toads and flogs—can synthesize toxins that attack the nervous system of predators. Other animals acquire chemical defenses passively. For example, some caterpillars acquire poison from the plants they eat. Then, when a bird eats the caterpillar, the bird quickly vomits. After that, the bird will avoid eating that kind of caterpillar. Some birds can remember bad-tasting meals a year later.
Another defensive adaptation is warning coloration. Animals with effective chemical defenses are often brightly colored, and there is evidence that predators are more cautious in dealing with bright color patterns in potential prey. This is probably because a lot of poisonous or bad-tasting animals are colored brightly, with black and yellow, or black and red stripes.
Warning coloration quickly trains predators to avoid eating these brightly-colored animals. Some birds have an instinctive tendency to avoid eating insects with warning coloration. For example, young warblers leave wasps alone because the birds recognize the danger in the black and yellow stripes of the wasp. However, warning coloration is not an absolute defense, as there is also evidence showing that many birds occasionally feed on bees and wasps, perhaps after learning to cope with their chemical defenses.
选项
A、How predators find, catch, and eat prey
B、Behaviors that help prey avoid predators
C、Changes in predator and prey populations
D、Defensive coloration in prey animals
答案
BD
解析
The professor discusses behaviors that help prey avoid predators: Prey species have adaptations, too--physical and behavioral adaptations that enable them to elude predators and avoid being eaten; ... hiding...; ... escaping...,... running away...; ... alarm call...; ... mobbing. The professor also discusses defensive coloration: Some animals rely on defensive coloration; Another defensive adaptation is warning coloration. (2.1)
转载请注明原文地址:https://tihaiku.com/zcyy/3333960.html
相关试题推荐
[img]2012q1/ct_eilm_eillist_0031_20121[/img][br][originaltext]ADVISOR:Isthe
[img]2012q1/ct_eilm_eillist_0031_20121[/img][br][originaltext]ADVISOR:Isthe
[img]2012q1/ct_eilm_eillist_0031_20121[/img][br][originaltext]ADVISOR:Isthe
[img]2012q1/ct_eilm_eillist_0031_20121[/img][br][originaltext]ADVISOR:Isthe
[img]2012q1/ct_eilm_eillist_0017_20121[/img][br][originaltext]Okay,nowg
[img]2012q1/ct_eilm_eillist_0017_20121[/img][br][originaltext]Okay,nowg
[img]2012q1/ct_eilm_eillist_0017_20121[/img][br][originaltext]Okay,nowg
[img]2012q1/ct_eilm_eillist_0399_20121[/img][br][originaltext]IfI’vepersuad
[img]2012q1/ct_eilm_eillist_0339_20121[/img][br][originaltext]DAWN:We’vecha
[img]2012q1/ct_eilm_eillist_0339_20121[/img][br][originaltext]DAWN:We’vecha
随机试题
Jobsinthe21stCenturyWhatwillourworldbelike
AlthoughFrench,German,AmericanandBritishpioneershaveallbeencredite
Forthispart,youareallowed30minutestowriteanessay.Supposetherearet
模板拆除的一般顺序是()。A.先支的先拆B.先支的后拆C.后支的先拆D.
孕激素不具有下列哪一作用()A. B.能促进乳腺腺泡发育,为哺乳作准备
根据资本资产定价模型在资源配置方面的应用,以下正确的有( )。 Ⅰ.牛市到来
A.石菖蒲 B.远志 C.龙骨 D.酸枣仁 E.合欢皮具有化湿开窍、宁心
承诺生效的地点为合同成立的地点。
人格特质理论中的四体液说将人的类型分为( )。A.多血质 B.胆汁质 C.
(2015年真题)某施工项目部根据以往项目的材料实际耗用情况,结合具体施工项目要
最新回复
(
0
)