A. According to modern ideas, the first step in the origin of life was
volcanic activity
b. the formation of simple organic molecules
the
presence of
oxygen in Earth's environment
d. the evolution of autotrophic prokaryotes
C. the presence of oxygen in earths environment
D. the evolution of autotrophic prokaryotes

Acladogram is a branching diagram that represents suggested evolutionary relationships among organisms based on the presence of unique traits. a scientist discovers a new organism that lacks limbs and does not have a true backbone. the organism lays eggs to produce offspring and has a cartilage-like rod known as a notochord running along its dorsal surface. on the cladogram below, select the species to which the newly discovered organism is most closely related.

Ageologist determines that a sample of a mineral cant be scratched by a steel nail but can be scratched by a masonry drill bit based on this information the sample mineral has to be softer than

Which statement describes john tuzo wilson’s contribution to the theory of plate tectonics?