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.

Juan and carol were studying invertebrates in biology. they knew that segmented or earth worms preferred a dark, moist habitat. during this lab, they would be investigating the responses of organisms called planaria or dugesia tigrina. these were simple flatworms that still had a one-way digestive system and a very simple nervous system. juan and carol placed the planaria in a petri dish containing cool, distilled water that was partially covered with black paper. they shined a light on the dish. next, they removed the paper and placed a small amount of chicken liver at one end of the dish. they added a few large salt crystals to the water. finally, they added drops of hot water to the cool water in the petri dish. their results can be seen in the data table. according to their experiment, all but one conclusion is valid.

What problem would a person most likely have if her kidney did not work correctly?

Which of the following is caused by reproductive isolation within a species? a. a decrease in gene flow b. an increase in genetic flow c. a decrease in genetic drift d. an increase in gene flow