Unit Test Answers

Shifts in the rock layer locations cannot account for gaps in the rock record

Mammals evolved into larger organisms and began subdividing into various species in the _____________.a.Mesozoic era c.Cenozoic era b.Paleozoic erad.Devonian era

Which best describes the fossil record?

Scientists notice structural similarities between fossils of a land animal and an aquatic organism. They know the similarities are not a result of the two organisms having to adapt to similar environments. What can they attribute the structural similarities to?

Complex organisms with gills and lungs were major life forms that existed in the_____________.a.Mesozoic era c.Precambrian era b.Cenozoic erad.Paleozoic era

Eons, eras, periods, and epochs, are all examples of ____________time. a.relative c.geographic b.geologicd.plate tectonics

______________ can be used to date fossils in rocks to give an approximate age. a. isotope c. radiocarbon dating b. half - life d. direct dating Please select the best answer from the choices provided

Why are the Miller-Urey experiments essential to the theory of evolution?

Thylacosmilus is a marsupial, and Smilodon is a mammal. Thylacosmilus and Smilodon both have saber teeth, but they do not share an ancestor that had saber teeth. What are saber teeth for these organisms?

____ is a process by which organisms with characteristics suited to the environment will survive and reproduce.a.Natural selectionc.Evolutionb.Artificial selectiond.Organic evolution

Trilobites are index fossils because they ____.a.changed slowly through timec.exhibit specific characteristicsb.lived over large areas of the worldd.all of the above

Changes in the environment result in ____.a.geologic erasc.plate tectonic changesb.physical changes in speciesd.all of the above

Which statement is true of the undisturbed rock layers shown?

Please select the word from the list that best fits the definition

Please select the word from the list that best fits the definition

Rock layers are correlated if they both contain the same ____.a.elementsc.fossilsb.shapesd.type of rock

The longest subdivision in geologic time is a(n) ____.a.epochc.centuryb.periodd.eon

The Cenozoic was a time of _______.a.mountain buildingc.global warmingb.continental breakupd.slow, global extinctions

Little is known about much of Earth’s early history because ____.a.Precambrian rocks have been deeply buriedb.Precambrian rocks have been changed by heat and pressurec.Precambrian soft-bodied life-forms weren’t often preserved as fossilsd.all of the above

Scientists used major changes in life forms in the fossil record to form the geologic time scale.