The way something is shaped or constructed

Any differences in traits between individual organisms

A characteristic that all organisms of the same species have

eyes in humans

green eyes, brown eyes, or blue eyes

hair on a human head

curly, straight, wavy, thick, thin hair

webbed feet in ducks

bird wings

Length of bird wings

bird feathers

bird feather color, length, thickness, texture

dog ears

dog ear size, floppiness, perkiness