Exam 13: The History of Life

Upon examining specimens recovered from the small intestine of a murder victim during the autopsy, you find clusters of cells that are attached to each other by shared cell walls. The outer layers of these cells are covered with a waxy cuticle, and there is evidence of many green organelles inside the more intact cells in the clusters. What type of cells would you propose you are examining?

The mass extinction at the end of the Cretaceous period about 65 mya is believed to have been caused by a massive comet or asteroid smashing into what is now known as the Yucatan peninsula in the Gulf of Mexico. The debris arising from this impact would have blocked the Sun's rays from reaching the Earth. How would this cause a mass extinction?

Imagine the discovery of an undescribed nonphotosynthetic, multicellular organism. To determine whether it is a(n) ________, you would need to examine it microscopically to determine if its ________.

The appearance of eukaryotes may have been delayed until more ________ accumulated in Earth's atmosphere.

The fossil record indicates that species have become extinct throughout the history of life. There have been five ________, during which greater than 50 percent of Earth's species became extinct.

Gymnosperms and angiosperms are believed to be more closely related to one another than the other major plant groups because

The domain ________ encompasses the traditional four kingdoms of Protista, Plantae, Fungi, and Animalia.

The most recent mass extinction, which occurred during the Cretaceous period, may have been caused by

Identify key characteristics for kingdom Fungi and provide three examples of members of this kingdom.

What is a likely reason the Cretaceous extinction about 65 mya is the best studied mass extinction?

In order to best determine relationships among different organisms, scientists would examine

In an evolutionary tree, a given ancestor and all its descendants make up a ________, or branch.

The current classification system used by biologists is

The emergence of each new branch on the evolutionary tree represents

The Cambrian explosion resulted in the evolution of more than 17,000 species of an animal known as the trilobite. The sheer number of trilobite fossils found in modern times suggests that trilobites were very abundant, perhaps the rulers of the seas. Today, no living descendants of this group exist. What happened?

Neighboring plant or fungi cells share a common cell wall, making multicellularity relatively simple. How do animal cells remain connected to one another?

How was the distribution of humans (after they evolved) affected by continental drift?

About 540 mya, there was an astonishing burst of evolutionary activity that correlated to the first appearance in the fossil record of most of the major living animal groups. Popularly known as the ________, this geologic time changed the face of life on Earth.

Correctly match the definition with the correct geologic time period. -Triassic

Correctly match the definition with the correct geologic time period. -Precambrian