Since the 1980s, Australian labor relations has become more centralized, focused more on national labor policy than on individual company-level bargaining.

A nauplius larva is characteristic of:

A) molluscs
B) gastropods
C) echinoderms
D) crustaceans
E) ctenophores

The most primitive vertebrates are ____.

A) jawless fishes
B) amphibians
C) cartilaginous fish
D) birds
E) bony fish

If Na⁺ cannot enter a muscle fiber in response to a stimulus,

A) contraction cannot occur.
B) relaxation cannot occur.
C) Na⁺ will be released from the sarcoplasmic reticulum instead.
D) the active sites are left exposed.
E) the action potential travels into the muscle anyway.

Echinoderms' radial symmetry enables which of the following?

A) An unusually rapid nutrient uptake
B) A greatly reduced metabolism
C) Rapid adaptation to extremes of temperature
D) An unusually long lifespan
E) The ability to respond effectively in every direction of their surrounding environment

The percentage of twins being born has increased in the past 20 years because of

A) the increased use of fertility inducing drugs.
B) increases in hospital care.
C) the desire of more couples to have twins.
D) the increased use of thalidomide.
E) the increased incidence of German measles.