Unconditioned reflexes are inborn, innate, natural.
Acquired reflexes develop after birth which depends on previous experience.
So an acquired reflex is a conditioned sudden, unprecedented response to a stimulus that a person becomes accustomed to due to the number of times it is repeated.
It is also called a conditioned reflex (eg: Pavlov's dog experiment).
Unconditioned is a sudden, unprecedented response to a stimulus that the person did not predict or foretell or was never trained to.
The response will become part of the muscle memory through repetition and repeated exposure to the same stimuli.
This unlearned response occurs in response to unconditioned becomes unconditioned acquired reflex.