Of what value are the septae (sheets of tissue) between segments of the earthworm?
a. They separate the individual units of the excretory system (nephridia) from each other.
b. They divide the nervous system into discrete units containing two ganglia and peripheral nerve axons.
c. Earthworms add segments to their back end as they grow and never lose the septa.
d. The edges of septa have sensory touch receptor that allow the earthworm to know when it is located in an appropriate environment.
e. Septa allow individual segments to swell and elongate when body wall muscles contract.