Unit Test — Unit test Answers

Study the diagram of the geologic time scale.Which method is most likely used to identify what happened before the start of the Paleozoic era?

Which evidence suggests that several mass extinctions have occurred during Earth's history?

A group of the same species of salmon lives in a stream. Which level of organization does this best describe?

During the nitrogen cycle, through which structure are nitrogen compounds first absorbed into the plant?

Several cheetahs are growling at each other while hunting for animals. For which need are they competing?

Which spheres of Earth are directly influenced when human-caused air pollution leads to acid rain that dissolves limestone rocks?

A tropical rainforest includes trees, animals, insects, plants, rain, rivers, rocks, soil, and warm, moist air.Which spheres of Earth are represented in a tropical rainforest?

Which is one piece of information that fossils in samples from Earth’s crust reveal about Earth’s history?

The diagram illustrates the water cycle.

Which phrase describes the relative age of a rock?

Rosa drew a flow chart of the carbon cycle.

Which information can be determined using half-life?

Which statement describes an effect that humans have on the geosphere when they build a dam?

After two half-lives, how much of the original material has decayed?

The image shows cross-cutting relationships. B, W, E, and K represent rock layers, and Q represents a fault.

Which best describes a role of animals in the water cycle?

The image shows flat sedimentary rock layers in the foreground and angled sedimentary rock layers in the background.

How is the nitrogen cycle important to humans?

Which example best explains the interaction of Earth’s spheres when acid rain affects trees?

Which is the first step in the process during the formation of molded fossils?