Fetal pigs are unborn pigs used in elementary as well as advanced biology

Biology

Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...

 classes as objects for dissection

Dissection

Dissection is usually the process of disassembling and observing something to determine its internal structure and as an aid to discerning the functions and relationships of its components....

. Pig

Pig

A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig, its ancestor the wild boar, and several other wild relatives...

s, as a mammalian species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

, provide a good specimen for the study of physiological systems and processes.
Along with frogs and earthworms, fetal pigs were among the most common animals used in classroom dissection. There are several reasons for this, the biggest being that pigs, like humans, are mammals.