From Wikipedia.org:
Zoology (Greek zoon = animal and logos = word) is the biological discipline which involves the study of animals.
Branches of biology relevant to zoology
The original branches of zoology established in the late 19th
century such as zoo-physics, bionomics and morphography, have largely
been subsumed into more broad areas of biology which include studies of
mechanisms common to both plants and animals. The biology of animals is
covered in several broad areas:
1. The physiology of animals is studied under various fields including anatomy and embryology
2.
The common genetic and developmental mechanisms of animals and plants
is studied in molecular biology, molecular genetics and developmental
biology
3. The ecology of animals is covered under behavioral ecology and other fields
4.
Evolutionary biology of both animals and plants is considered in the
articles on evolution, population genetics, heredity, variation,
Mendelism, reproduction.
5. Systematics, cladistics, phylogenetics,
phylogeography, biogeography and taxonomy classify and group species
via common descent and regional associations.
In addition the various taxonomically oriented-disciplines such as
mammalogy, herpetology, ornithology study mechanisms that are specific
to those groups.