Leap Science Geology

Before life evolved adaptations for living on the land, a major change in one of Earth's systems took place. Which of the following was a change that made it possible for life as we know it to live on the land?

• addition of carbon to ocean water
• addition of sodium to ocean water
• addition of oxygen to the atmosphere
• addition of ammonia to the atmosphere

Early in Earth's history, the composition of the atmosphere was quite different from what it is today. When did Earth's atmosphere change due to living organisms?

• Cenozoic Era 
• Mesozoic Era
• Paleozoic Era
• Precambrian time 

Early in the Paleozoic Era, plants began to colonize the continents. Which of the following changes to Earth's surface most likely happened as a result?

• sea level increased
• sea level decreased
• rates of erosion increased
• rates of erosion decreased

The table below shows some of the major events in Earth’s history. Which event marks the end of the Permian Period?

• extinction of the dinosaurs
• early human ancestors appear
• first animals with exoskeletons appear
• largest mass extinction event in Earth’s history

According to the fossil record, when did the dinosaurs become extinct?

• at the end of the Mesozoic Era
• at the end of the Paloezoic Era
• at the start of the Mesozoic Era
• at the start of the Paleozoic Era

What is the law of superposition?

• gneous rock is older than nearby sedimentary rock, which is older than nearby metamorphic rock.
• A sedimentary rock layer in its original position is older than the layers above it and younger than the layers below it.
• Metamorphic rock is older than nearby sedimentary rock because sedimentary rock is deposited before metamorphic rock forms.
• The exact age of a sedimentary rock layer can be found using the layers above and below it, even if the layers are not in their original positions.

How does the law of crosscutting relationships explain the age of a fault caused by an earthquake?

• The fault is older than the rocks above it.
• The fault is younger than the rocks above it.
• The fault is older than the rocks it cuts through.
• The fault is younger than the rocks it cuts through.

What is a geologic column?

• a rock structure that is shaped like a column
• a body of rock that cuts through sedimentary rock layers
• a group of rock layers that are taken out of the ground to study
• a group of rock layers that are placed in order of their relative ages

Fossils are the preserved remains or traces of plants and animals that have lived on Earth throughout Earth’s history. How does the fossil record of animals compare to animals that exist today?

• Animals in the fossil record are the same as animals that exist today.
• Animals in the fossil record are ancestors of animals that exist today.
• Animals in the fossil record have no similarities to animals that exist today.
• Animals in the fossil record are more complex than animals that exist today.

The following diagram shows rock layers that are cut by a fault and two bodies of rock (rock 1 and rock 2). What are the relative ages of the features in order of oldest to youngest?

• fault, rock 1, rock 2, layer 1
• layer 1, rock 2, rock 1, fault
• rock 2, layer 1, rock 1, fault
• fault, rock 2, layer 1, rock 1