Indeed. The choice of a combination of aperture and shutter speed is critical to ensure that the subject has sufficient depth of field and degree of (or absence of) motion blur. In aperture or shutter priority the photographer has direct control over this, but in reality in program the photographer generally has a similar level of control with (D)SLRs these days; the camera's chosen settings are displayed in the viewfinder, and can generally be modified by the photographer with a twirl of the input wheel if they're not optimal.