Here is all you want to know about English! Start your FREE email English course now!
range; extent; sphere; expanse
full quiz correct answer

TOEFL listening: A university lecture on Animal Behavior by a professor of Biology

Overview of TOEFL listening part
TOEFL lecture 1
TOEFL lecture 2
TOEFL lecture 3
TOEFL lecture 4
TOEFL lecture 5
TOEFL lecture 6
TOEFL lecture 7
TOEFL lecture 8
TOEFL lecture 9
TOEFL lecture 10
TOEFL lecture 11
TOEFL lecture 12
TOEFL lecture 13
TOEFL lecture 14
TOEFL lecture 15
TOEFL lecture 16
TOEFL lecture 17
TOEFL lecture 18
TOEFL lecture 19 — Script Q&A
TOEFL lecture 20
TOEFL lecture 21
TOEFL lecture 22
TOEFL lecture 23
TOEFL lecture 24
TOEFL lecture 25
TOEFL lecture 26
TOEFL lecture 27
TOEFL lecture 28
TOEFL lecture 29
TOEFL lecture 30
TOEFL lecture 31
TOEFL lecture 32
TOEFL lecture 33
TOEFL lecture 34
TOEFL lecture 35
TOEFL lecture 36
TOEFL lecture 37
TOEFL lecture 38
TOEFL lecture 39
TOEFL lecture 40
TOEFL lecture 41
TOEFL lecture 42
TOEFL lecture 43
TOEFL lecture 44
TOEFL lecture 45
TOEFL lecture 46
TOEFL lecture 47
TOEFL lecture 48
TOEFL lecture 49
TOEFL lecture 50
Conversations (50 audio exercises)
Lectures (50 audio exercises)
Prep forum for the TOEFL test
English Language Exercises 2206 English Exercises
This English grammar test package will help you learn new phrases, idioms, expressions and grammar structures every single day. And you won't even have to cram any grammar rules or vocabulary words into your head. Instead, you will be absorbing bits and pieces of the English language almost without realizing it.
Get FREE English course via e-mail 
50 TOEFL lectures   50 TOEFL conversations
Listen to a conversation 37438 listened   

Please activate Flash to use MP3 player.

Improve your progress in learning English! —
These users have taken this test.
Next users >
See progress report of Kolli.vamsikrishna

one year ago
See progress report of Yohis04

one year ago
See progress report of Igor_Yankin

one year ago
See progress report of Htsondk251

one year ago
Do you want to be in this list? Please register on our forum und take the tests with your own progress report!

50 TOEFL lectures
50 TOEFL lectures
A great variety of English listening comprehension tests that will help you increase your TOEFL test score.
  • based on TOEFL academic lectures
  • written and recorded by experienced US authors and voice-over specialists

  • TOEFL Preparation tests Increase your TOEFL test score with
    120 Vocabulary + 100 Grammar tests
    600 word flashcards plus an ESL book
    Dear Friend,
    if you have any questions or comments regarding this article, please click here: Wanted: Feedback on TOEFL Listening Exercises.
    50 TOEFL lectures   50 TOEFL conversations

    TOEFL Listening Comprehension Transcript

    Listen to part of a university lecture on Animal Behavior by a professor of Biology.

    Professor: We're looking at animal behaviour this week, and let's turn now, class, to one of its most dramatic manifestations- animal mimicry. Organisms that are good to eat, or that are attacked for other reasons, often develop devices- through evolution, of course- techniques and devices to protect themselves from their attackers, in order to survive, and in order to reproduce and pass their genes on to the next generation. And one of these techniques, one of these strategies, is to look like something else, to look like something that is not good to eat, or something that is otherwise of no interest to the predator. An organism that does this, that resembles something else, is called a 'mimic', and the thing that it has evolved to resemble is called the 'model', while the predator that it is trying to mislead is called the 'recipient'- the one that receives the misleading image.

    Some mimics do this by adopting camoflage, which is a cryptic resemblance to something of no interest to its enemy, and by doing this, they become invisible, they are hidden. Many animals- insects, lizards, amphibians- mimic the abundant plant life in the habitat around them. I'm sure that you've seen green grasshoppers and brown moths that seem to be well-hidden on grass stems and tree trunks when they're motionless. But the Leaf-tailed Gecko, a small lizard in Madagascar, is a master at this. It avoids its enemies by looking exactly like a cluster of old dead leaves. And there are various species of katydids, grasshopper-like insects, that have managed to duplicate the appearance of leaves with startling accuracy, in all stages of growth, some species looking like fresh green leaves and others looking like old decaying leaves- complete with leaf veins, weathered edges and mildew spots! These adaptations make these animals difficult or impossible for a predator to identify or even notice, and so these otherwise defenseless creatures are overlooked or passed by.

    Other organisms defend themselves directly with stings or bites, or with poisons or other noxious chemicals, and such organisms often assume bold, characteristic colors and markings- called warning coloration- that warns a predator, reminds it, that this creature can inflict pain or discomfort, or that it tastes very bad. The bold orange-and-black pattern of the common Monarch Butterfly, or the black-and-yellow bands on a bumblebee, are such warning colorations.

    And sometimes, this warning coloration is so effective that another species, a species that doesn't have any of the protective devices of sting or poison or whatever, will adopt the same warning colors and pattern. This sort of mimicry is called 'Batesian mimicry'. The name comes from the early zoologist, HW Bates, who, back in 1862, first suggested an explanation for the origins of mimicry based on Charles Darwin's new Theory of Natural Selection. This was one of the earliest applications of Darwin's ideas to an unknown biological phenomenon.

    Now, Viceroy Butterflies taste good to many birds, but because they mimic the Monarch Butterfly model's color pattern, because Viceroy Butterflies look like Monarch Butterflies, they are avoided, just like the Monarch is. In the same way, many harmless fly species resemble the bumblebee model, and also in this way they avoid being eaten by the recipients, birds. So these are Batesian mimics. There are several conditions that must be fulfilled, though, for a Batesian mimic to be successful- the mimic must of course share the same general region and habitat as its model, but the mimic must also be less numerous than its model, which must be relatively abundant. That way, the odds are that the recipient predator will sample an unpalatable model first, which is very important for keeping the trick effective.

    A similar kind of mimicry is 'Müllerian mimicry'- named after another early biologist- and in this sort of mimicry, both the model and the mimic are dangerous or taste bad. A very obvious example is the way that so many unrelated species of bees, wasps, and ants have assumed similar, bold, black-and-yellow or black-and-orange banded patterns. By doing this, Müllerian mimics present a united image that predators soon learn to be wary of.

    There's also another aspect of mimicry that I'd like to mention, too, and that's the mimicry used by predators. This is called 'aggressive mimicry', and it is used to conceal or misrepresent a predator until its prey comes near enough to capture. Many mantids, for example, are green or brown, so that they blend in with their plant surroundings, but some tropical mantids are fantastically shaped and colored, like the beautiful Orchid Mantis, which resembles a petal of one of those tropical flowers, and it hides motionless next to one of these orchids until an insect comes within its reach. There're also several green-colored vine and grass snakes of various families, which lie invisible among the tangled vines and branches of the jungle until they suddenly lash out to grab their prey.

    Actually, there are an endless number of ingenious mimics in the natural world, and I recommend that you all try a Google Images search tonight for some more interesting examples of this fascinating behaviour.

    50 TOEFL lectures
    50 TOEFL lectures
    A great variety of English listening comprehension tests that will help you increase your TOEFL test score.
  • based on TOEFL academic lectures
  • written and recorded by experienced US authors and voice-over specialists
  • 50 TOEFL lectures   50 TOEFL conversations

      copyright © 2003—2019  
    Get FREE English course via e-mail