Life forms in the Precambrian include
A) trilobites, brachiopods and stromatolites.
B) cyanobacteria and trilobites.
C) the agnatha and the coelacanths.
D) stromatolites and certain primitive blue-green algae.
Answer: D
You might also like to view...
When two objects of unequal mass orbit each other, the center of mass is ____
a. at the center of the more massive object b. at the center of the least massive object c. half way between the centers of each object d. always closer to the less massive of the two objects e. always closer to the more massive of the two objects
Over withdrawal of groundwater causes ground subsidence in areas
A) of karst topography.
B) underlain by unconsolidated sediments.
C) underlain by consolidated sediments.
D) all of these
What is the ionization energy of the neutral hydrogen atom?
A) 27.2 eV B) 13.6 eV C) 6.8 eV D) none of the given answers
Consider the decay ?o ? ?- + e+. This decay is
A) forbidden because conservation of baryon number is violated. B) forbidden because conservation of lepton numbers is violated. C) allowed. D) forbidden because conservation of mass is violated. E) forbidden because conservation of energy is violated.