Maintaining their body temperature is the one of basic principles of animals.
Animals despite their varying evolutionary histories and varying complexity must solve the general challenges of life in obtaining food, oxygen, nourishing themselves, excreting waste products, and their movement from place to place.
Animals inhabit almost every part of the biosphere. Despite their great diversity,
all animals must solve a common set of problems. All animals must obtain oxygen,
nourish themselves, excrete waste products, and move. Animals of diverse evolutionary
histories and varying complexity must solve these general challenges of life.
concepts such as Form and Function; Organs and Organ systems; Metabolism–a set of chemical reactions to harvest and use energy; Bioenergetics –how organisms obtain,
process, and use their energy resources; Homeostasis –steady state or internal balance,
helps us to understand the common principles which underlie various life processes.
Anatomy is the study of the structure of an organism and Physiology is the study
of the functions an organism performs. Natural selection can fit structure to function
by selecting, over many generations, what works best among the available variations
in a population.
Form and function: Physical laws and the environment constrain animal size and shape. An animal’s size and shape, features that biologists often call "body plans" or "designs" are fundamental aspects of form and function that significantly affect the way an animal interacts with its environment. By using the terms plan and design here, we do not mean to imply that animal body forms are products of conscious invention. The body plan of an animal results from a pattern of development programmed by the genome, which is the product of millions of years of evolution. The possibilities are not infinite as physical laws and the need to exchange materials with the environment place certain limits on the range of animal forms.