They are made up of eukaryotic cells, i.e., they contain a well defined nucleus and membrane bound organelles. They lack plastids and contain small and large number of vacuoles.
Cell wall:
Cell wall is absent. Plasma membrane is the outermost layer in animal cells which is made up of proteins and lipids.
Body organization:
They are multicellular organisms. The cells may be differentiated into tissues/ organs. On the basis of differentiation, they are further classified into different groups. Body is well organized in higher organisms.
Locomotion:
Organisms of kingdom animalia are usually motile. Locomotion in higher organisms occur with the help of muscular system. However lower organisms are not motile.
Mode of nutrition:
Animals are heterotrophic, i.e. they are unable to synthesize their own food hence obtain it from outside and digest it inside the body by intracellular or extracellular process. The reserve food material in these organisms is glycogen.
Reproduction:
Lower animals reproduce by asexual mode while higher animals reproduce by sexual mode.
