Which statements describe processes involved in the accretion of planetesimals and protoplanets? Check all that apply. Both involve the melting of solid materials in the nebula.
Both involve the formation of solid particles from nebular materials.
Both involve the work of the gravitational push on nebular materials.
Both involve the trapping of gases and the clumping of masses of matter.
Both involve the growing of gas grains with the addition of atoms and molecules.

Cladistics is a way of classifying organisms by examining the characteristics of their ancestors and descendants and depicting the relationships in a cladogram. which of the following best describes a challenge in classifying organisms this way? a. there are millions of species on earth, and a cladogram is not a practical means for classifying all of them. b. it is impossible to tell which organisms are most closely related to each other using a cladogram. c. cladograms are detail-oriented and do not provide a useful understanding of evolutionary relationships. d. there is a limited number of ways to organize the information, so most cladograms end up looking very similar.