Ectotherms lecture 1 Flashcards
What are the three subphyla in the chordates?
Cephalochordates, urochordates and vertebrates
What are the major characteristics of the phylum of chordata?
Bilateral symmetry, segmented body, three germ layers, well developed coelom Notchord, Single, dorsal, tubular nerve cord Pharynegeal gill slits Post anal tail Segmented muscle Ventral heart Complete digestive system Cartilaginous or bony endoskeleton
What is the notochord?
Cartilaginous rod which is part of the axial skeleton in chordate embryo’s
In some animals it can make the “backbone”
What are the unique features of the subphyla vertebrata?
Living endoskeleton
Efficient respiration
Advanced nervous sytem
What is the difference between an ectotherm and an endotherm?
An ectotherm is an animal which relies on the environmental temperature and behavioural adaptation to maintain body temperature while an endotherm is an animal which uses heat from metabolism to regulate body temperature
What are the benefits of ectothermy?
It is a very low cost system meaning the animal has to eat less and has more energy available for reproduction and growth, this also allows the organisms to be very small
What are the disadvantages of ectothermy?
It is harder to maintain homeostasis and they are restricted to warm environments
What are the benefits of endothermy?
Consistent metabolic rate
Able to maintain activity
What are the disadvantages of endothermy?
It is a huge energy cost
How do terrestrial ectotherms have temperature regulation?
This is precisely controlled via behavioural adaptations such as entering and exiting a burrow, facing the sun to warm and head on to cool
What is the difference between homeotherms and poikilotherms?
A homeotherm is an animal that maintains a constant body temperature while a poikilotherm is an animal which has its body temperature vary considerably
What are the four different types of heat exchange which can occur between an organism and its environment?
Radiation, convection, evaporation and conduction
