Because they have G protein controlled ion channels to produce the RMP

Because they generally have leakier membranes and have a standing current flow

Because they have cascade amplification systems that influence the flow of ions

Because they depend on different types of ion channels to produce the RMP

Because of the different fluid and chemical environment in which they exist compared to neurons

only APs involve the opening of voltage-gated ion channels.

only APs are produced by receptor cells.

only APs involve a depolarization of the cell membrane.

RPs / GPs are always produced by closing of open ion channels.

only APs depend on movement of Na+ ions into the cell.

It involves relaying sensory information via APs in neurons

It results in a decrease in responsiveness to a maintained constant stimulus

It allows summation of responses to indicate stimulus timing

It involves the release of transmitter to underlying nerve fibres

It requires the entry of Ca++ into the receptor cells during the production of the receptor potential

Rapid but not slow stimulus change 

Stimulus changes and duration

Stimulus size and duration

Stimulus size or duration, but not both

Stimulus quality

And this underlies their ability to signal the timing of stimuli

Because they only have short refractory periods

Because they also have voltage-gated channels

Because they occur pre-synaptically

Because they occur on dendrites

The conversion of non-biological sensory energy into a biological response

The biological response produced in systems without receptor cells

The conversion of biological energy into a non-biological sensory response

The conversion of a response in receptor cells into APs in nerve fibres

The relaying of nerve APs to the brain

Different accessory structures translate information in different way

Different neurons adapt to the same stimulus in different ways

Different receptors signal different strengths of the stimulus range that we can detect

Different neurons have different thresholds to the stimulus over the range we detect

Different receptors signal different parts of the stimulus range that we can detect

Stretch-activated ion channels only

The neurons

The receptor cells

The accessory structures

G proteins