Unit Test — Unit test Answers

A scientist is trying to determine the relationship between clams, snails, and squid. When she generates a molecular clock, she is surprised to see that clams and squid are more closely related than clams and snails. Which did the molecular clock data show?

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

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?

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?

In a cladogram, when does a group of organisms branch off?

Which best explains a primary reason for the inability of life to exist in Earth’s early atmosphere?

Which phrase describes the relative age of a rock?

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

Which best describes traditional classification?

Mr. Morales is teaching a lesson on classification. He says that spiders are classified as a different group than insects because they have eight legs instead of six legs. He explains that spiders evolved first. Mr. Morales also says that having eight legs is the derived trait that separates the two groups. Antonio thinks Mr. Morales is wrong. Which piece of information is Antonio considering?

Which best describes eras and periods?

Which best describes derived characteristics?

Consider the diagram.Josiah says this is a phylogenetic tree of the dinosaurs. Maleek says it is a cladogram of the dinosaurs. Who is correct?

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

Which feature causes a gap in the geologic record?

A geologist finds four layers of sedimentary rock. She determines that no geologic events have shifted the layers. She labels the layers A, B, C, and D from the top to the bottom.Which statement about these layers is accurate?

What do gradualism and punctuated equilibrium have in common?

What information does the geologic time scale provide about Earth's history?

Australopithecus is an ape that lived in trees, but could walk on two feet. How might fossils from Australopithecus provide evidence for evolution?

Dogs have a reduced nonfunctional digit on their paws known as a dewclaw. What is this an example of?