The answer is B - experimental group .
The echinoderm with long spines
belongs to the class Echinoidea which includes sea urchins, heart urchins, cake
urchins and sand dollars. This spine serves as their protective mechanism from
predators. The spines are joined to the skeleton and muscles surround it. The muscles
enable them to swivel its spines from predators.
Answer:
2.) sequence of the subunits in the base sequence of the DNA
