Exam 24: The History of Life on Earth

The elimination of many forms of life following a meteorite impact led to new opportunities for mammals to evolve into a diversity of forms.As a result of this historic event, most of human evolution has occurred during the

The _______ dating method makes use of changes in the patterns of Earth's magnetism to determine the age of rocks.

The preserved remains of ancient organisms, known as _______, are more abundant for organisms that are numerous and/or hard-bodied.

What would you not expect to see in the early Cambrian?

The end of the _______ was marked by the largest mass extinction of life in the history of Earth.

Which statement about stratigraphy is false?

The ratio of carbon-14 (¹⁴C) to its stable isotope, carbon-12 (¹²C), is relatively constant in living organisms and their environment; however, this changes once an organism dies.In a fossil approximately 40,000 years old,

Refer to the graph showing the decay of a radioactive substance. The half-life of this substance is _______ years.

During the Cenozoic, _______ experienced major radiations.

The world's oldest recorded living tree is a 9,550-year-old spruce in the Dalarna province of Sweden.Scientists have also found cones from the same site that date back over 9,000 years and have the same genetic identity as the tree.These ages were determined using carbon-14 dating at a laboratory in Miami, Florida.If the ratio of ¹⁴C to ¹²C in the tree and the cone samples were compared, the ratio would be

Refer to the figure. The process of subduction, which is illustrated in the figure, is most relevant to the formation of

A layer of rocks is known as

In 2006, paleontologists announced that fossils of Tiktaalik roseae, an important link between fish and tetrapods, had been discovered in freshwater sediments in the Canadian Arctic that were 375 million years old.How were geologists able to determine the age of these sediments?

Large glaciers overtaking much of the higher latitude continents, extensive swamp forests growing on the tropical continents, and the diversification of terrestrial animals, were hallmarks of the _______ period.

The high oxygen concentrations during the Carboniferous and Permian periods led to _______ insects.

A paleontologist discovers a stromatolite and suspects that its older layers may contain fossils more than 3 billion years old.Which method will likely produce the best estimate of its age?

Which statement about radioisotope dating is false?

The first prokaryotic organisms evolved during the _______ eon.

Suppose you were to drill a hole toward the center of Earth.Which of the following is the correct order of the layers you would encounter?

Prokaryotes probably first added significant quantities of oxygen into the atmosphere when they