The proprioceptors are the sensors in the limbs, which give information regarding the muscle length, joint angle, and muscle tension that is combined to provide knowledge regarding the alignment of the limb in space. The muscle spindle is one of the kinds of proprioceptor, which gives information regarding the changes in the length of the muscle.
On the other hand, a nociceptor refers to a sensory neuron, which reacts towards the potentially damaging or destructing stimuli by conducting probable danger signals towards the brain and the spinal cord.
Proprioceptors are to reflex actions as nociceptors are to pain perception.
Pioneer species can decrease if other species move it out. If the pioneer species in a forest area is a type of bush, that bush might decrease in number as more species come in.
No that is just, no just no. DNA is copied through cell reproduction where a cell splits to create more (growing for multi called organisms and asexual reproduction for single celled organisms) The mitochondria is an organelle that is the "power house" of the cell, the "digestive system".