Truth or false
16. Land organisms can be buried by mudslides, volcanic ash, or sand to eventually become fossilized.
17. Cross-cutting relationships helps geologists to determine the older and younger of two rock units.
18. Time is missing in a geologic section when there is an unconformity.
19. The largest mass extinction occurred at the end of the Cenozoic, when the dinosaurs died out.
20. All isotope pairs can be used to date any geological materials.
21. About fifty percent of all living organisms become fossils.
22. Changes in populations over time is biological evolution.
23. Prokaryotes are different from eukaryotes because they have a nucleus.
24. Present day life forms evolved from earlier life forms.
25. There is fossil evidence that modern horses evolved from an earlier animal.