Which example is a way that intercellular communication occurs?
A. A signal is sent down an exon within a nerve cell.
B. A molecule is sent through the plasmodesmata of a plant cell.
C. A signal is translated into action for a muscle cell to contract.
D. A molecule is transmitted from one part of a cell to another to cause a response.

Which statement describes characteristics of planarians? a they live in oceans, are parasites, and reproduce only sexually. b they live in fresh water, are parasites, and reproduce only asexually. c they live in oceans, are free living, and reproduce sexually and asexually. d they live in fresh water, are free living, and reproduce sexually and asexually.