2. How does photosensitivity
in cnidarians, annelids and
worms differ from insects,
cephalopods and vertebrates?

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
In the first mentioned of animals
there are cells organized
in ocelli diffusely dispersed in the
. These animals do not
images.

In the animals the second group the
cells are part of
sophisticated structures, the eyes,
to form images and send them to the
system.