The diagram shows different layers of sedimentary rock. Each layer is labeled with a letter.Which statement correctly describes the relative ages of the rock layers shown in the diagram?

A teacher gave students this diagram of rock layers. The teacher directed the students to determine the relative age of each rock layer based only on the information presented in the diagram.Which method can BEST be used by the students to determine the relative age of these layers?

Which of the following BEST describes the fossil at Point 3 when compared with the fossils at Points 1 and 2?

The radioactive isotope content of a rock can be used to identify which property of the rock?

Which method would be BEST for scientists to use to determine the absolute age of a Precambrian igneous rock?

Which of these provides the BEST evidence that the distribution of Earth’s oceans has changed over time?

A fossil discovered in Colorado dates from the early Mesozoic era. A year later a similar fossil is found in Wyoming that also dates from the early Mesozoic era. These two organisms most likely lived in

Which of the following eras is known as the “Age of Mammals”?

Certain fossils can be used to help determine the age of the rock layer in which the fossils are found. Which type of fossil is BEST to use when making this determination?

Scientists estimate that if index fossils were deposited during a certain time frame, then the entire rock layer was also deposited at the same time. A scientist finds Trophite fossils. According to the chart above, in what era and period was this rock layer deposited?

Which environmental condition MOST likely existed at the time a fossil formed?

Scientists discovered fossils of different organisms in some layers of rock. Organism 5 was discovered in the uppermost layer. The scientists wanted to determine if Organism 5 was related to other organisms found in older layers of rock. They compared physical traits and DNA similarities from all the fossils. Some of their results are shown in the table.

Based on the table, which organism is MOSTlikely an ancestor of Organism 5?

Which evidence would BEST indicate that four-legged land animals might have a fish ancestor?

Which of these would help determine the changes in a plant species over geologic time?

A complete fossil has been found of a type of bird that cannot be identified. What can MOSTlikely be determined about the bird from the fossil?

Scientists theorize that the ancient animal on the left is related to the modern animal on the right and has gone through many changes over time. How did the scientists conclude that the animal changed over time?

Which of these characteristics BEST helps scientists classify organisms?

Imprints of the shells of ocean clams are often found in the rocks of the Appalachian Mountains. What do these imprint fossils MOST likely indicate?

Scientists dug through three layers of rock and found many rabbit fossils. The fossils were complete enough to determine the length of the rabbits’ hind feet. Consider the data in the table. Which conclusion is BEST supported by the data?

Scientists studied the taxonomic relationship between two lizard species living on the sides of a canyon. One species had long toes and one had short toes, but they were alike in most other ways. The table shows what the scientists found. What is the MOST likely reason for these findings?

Scientists estimate that whaling activity in the 19th and early 20th centuries had reduced the number of adult female southern right whales to as few as sixty individuals by 1920. This reduction resulted in a genetic bottleneck for the species.

Treaties to stop whaling have substantially increased the number of southern right whales. Despite this increase, the bottleneck still threatens the future of the species. Which capacity of the species is MOST severely diminished by the bottleneck?

Wild blackberries reproduce asexually by sprouting new roots when stems touch the ground. They also reproduce sexually through their flowers. What is the advantage of the blackberry plant being able to reproduce sexually and asexually?

Which of these adaptations is LEAST important for human survival?

Charles Darwin made famous observations of finches on islands in the Pacific Ocean. The birds were believed to have come all from one population, but when separated on the islands with differing habitats, the birds changed. The beaks of the birds on islands with lots of seeds were different from the beaks of the birds on islands with lots of insects. How did their beaks come to match the food in their environments so well?

In the winter, the fur of the arctic fox is white. In summer, the fur darkens to a reddish brown. What most likely causes the fur of the fox to change color?

A strawberry farmer finds that, after a hard freeze, some of his strawberries are still alive. Which best explains why these strawberries were able to survive?

Which would best allow a species to survive environmental changes?

Tigers and household cats are members of the same family; however, their sizes are vastly different. What is the cause of this difference?

Which bird’s beak is best adapted to get nourishment from the nectar of flowers?