There are two types of waves: mechanical and electromagnetic. Microwaves, infrared waves, and radio waves are examples of electromagnetic waves. Which claim is TRUE about
the speed of electromagnetic waves?
A: They are not affected by changes in medium.
B: It is slower in a vacuum than in a medium.
C: In a vacuum, its speed equals half the speed of light.
D: It slows down when it goes from a vacuum to a medium.

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.