How many embryonic and adult tissue layers are found in jellyfish, hydras, and sea anemones?
a. 1
b. 2
c. 3
d. 4
a. specialized vascular tissue.
b. absorption alone.
c. absorption and transpiration.
d. osmosis and diffusion.

Classify the structures as homologous or analogous, depending on their structure and function.

The fish shown above is a tarpon. it is a fast-swimming and powerful open-water fish. its closest relatives, oddly, are burrow-dwelling conger eels that stay on the bottom. both eels and tarpon developed from snake-like larvae that float in the plankton during the first stages of life. once they mature, tarpon and eels are not found near one another in the ocean. the tarpon and the eel illustrate all of the following except

How can you tell the difference between rough er from smooth er?