Answer:
a) Maxillopoda is a diverse class of crustaceans including barnacles, copepods and a number of related animals. It does not appear to be a monophyletic group, and no single character unites all the members
b) General Characters of Hexapoda (Insects)
Ø A large taxa, includes insects and a small group of wingless arthropods.
Ø Body plan: 3 parts, head, thorax and abdomen.
Ø Head with six segments.
Ø Thorax with three pairs of jointed legs (hence the name hexapoda)
Ø Head bears a presegmental acron.
Ø Acron bears compound eyes.