There are different types of nerves or mechanoreceptors located in your skin. nerves that detect deep pressure are called

merkel's disks
meissner's corpuscles
pacinian corpuscles

Nerves that detect deep pressure are called Pacinian corpuscles.

Pacinian corpuscles are microscopic onion-shaped nerve structures that are situated in the dermis and hypodermis. Pacinian corpuscles detect deep pressure and vibration. This nerve has a myelinated nerve ending in the middle of its structure and the external layer contains flattened cells, a lymph-like fluid and collagen fibers. The structure of pacinian corpuscles provides a fast response and rapid recovery by transmitting fast events. This make them sensitive to pressure and vibration.

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.