The endocrine system or the skin (:
The answer is that they do not live on or in the body of a host.
Symbiosis is the ecological relationship between two or more organisms living closely together with some form of feeding relationship involved. The three main symbiotic relationships are: - Mutualism, where both organisms benefit. - Commensalism, where one organism benefits while the other organism is not harmed. All of them thrive off of the other organism.
Answer: Option B.
Neural crest and peripheral nervous system.
Explanation:
Neural crest are bilateral paired cells of the neural tube that arise from the ectoderm layer of the embryo. Thesescells move to different part of the body and differentiate into various cell types like melanocytes,cartilage and bone, smooth muscle, craniofacial, neurons, gangalia e.t.c. The neural crest running through neural tube develop into peripheral nervous system after birth. Peripheral nervous system consist of neurons and gangalia outside the nervous system The peripheral nervous system connect the central nervous system to organs, skin and limbs.
