Which is a characteristic feature of the members of the group tunicata?
a. they regulate water with of a siphon.
b. they have a tough calcium carbonate exoskeleton.
c. they feed on phytoplankton using tentacles.
d. they possess a water vascular system.

The answer is B. They have a tough calcium carbonate exoskeleton.

yes it is   dangerous

explanation:

because that foot is discusting and could get you sick

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.