Class Notes (836,580)
Canada (509,856)
York University (35,328)
Biology (2,253)
BIOL 1602 (40)


2 Pages
Unlock Document

BIOL 1602
Rebecca Jubis

 Vast majority of organisms are ectothermic, means that their body temperatures are determine by the temperatures of their environments  Body temperature has a profound effect on an ectotherm’s physiological performance  Desert iguanas can survive short exposures to body temperatures as low as 0ºC and as high as about 47ºC o They can only function between about 15ºC - 45ºC  Within this range, cold iguanas run and digest slowly, tire quickly, and hear poorly  As they get warmer, they run and digest more quickly, tire more slowly, and hear more keenly  The relationship between physiological performance and temperature is called a thermal performance curve  Given the sensitivity of physiological function to temperature, we can predict that ectotherms will exhibit behavioural thermoregulation  Ectotherms should move around in the environment so as to maintain themselves at or near the temperature at which they perform the best  As temp. Of their environment changes, iguanas must regulate their body temperature by moving into the sun to warm up or into the shade to cool off o Iguanas prefer to keep their body temp. In the high 30s; this is the center of the range of temperatures at which the iguanas perform best  To prove behavioural thermoregulation, we must show: o That the animal in question is choosing particular temperatures more often than it would encounter those temperatures if it simply moved at random through its environment o That its choice of temperatures is adaptive Do Garter Snakes Make Adaptive Choices When Looking for a Nighttime Retreat?  Snakes have many options for thermoregulation during the daytime, as long as they avoid thin rocks or direct sun in the afternoon  At night, however, it appears that the b
More Less

Related notes for BIOL 1602

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.