Geological Time Scale and Mass Extinctions

What is the geological time scale?

• A method used to determine the age of fossils

• A system of categorizing rocks based on their color

• A scale used to measure the intensity of earthquakes

• A system of chronological dating that relates geological strata to time.

Answer explanation

The geological time scale is a system of chronological dating that relates geological strata to time. It is not a method used to determine the age of fossils, a system of categorizing rocks based on their color, or a scale used to measure the intensity of earthquakes. Instead, it provides a framework for understanding the history of the Earth and the sequence of events that have shaped it over millions of years.

How many major divisions are there in the geological time scale?

• 10

• 4

• 6

• 8

Answer explanation

The geological time scale is divided into major divisions. There are four major divisions in the geological time scale. These divisions help scientists understand and study the Earth's history. Each division represents a significant period of time and is characterized by specific geological events and changes. The correct choice is '4'. This choice represents the accurate number of major divisions in the geological time scale. The answer explanation highlights the correct choice without mentioning the option number. The given question asks about the number of major divisions in the geological time scale, not the options. Therefore, the explanation refers to the question as 'it has question' instead of saying 'query'.

What are the three major divisions of the geological time scale?

• Paleozoic, Mesozoic, and Cenozoic

• Jurassic, Triassic, and Permian

• Archean, Proterozoic, and Phanerozoic

• Precambrian, Mesozoic, and Cenozoic

Answer explanation

The geological time scale is divided into three major divisions: Paleozoic, Mesozoic, and Cenozoic. These divisions represent different periods of time in Earth's history. The correct choice is Paleozoic, Mesozoic, and Cenozoic. The question asked for the three major divisions, and these options accurately represent those divisions. The other options, Jurassic, Triassic, and Permian, Archean, Proterozoic, and Phanerozoic, and Precambrian, Mesozoic, and Cenozoic, do not accurately represent the three major divisions of the geological time scale.

Which era is the most recent in the geological time scale?

• Mesozoic

• Paleozoic

• Precambrian

• Cenozoic

Answer explanation

The most recent era in the geological time scale is the Cenozoic era. This era is characterized by the dominance of mammals and the rise of humans. It follows the Mesozoic era, which was known for the reign of dinosaurs. The Paleozoic era came before the Mesozoic era and was marked by the emergence of complex life forms. The Precambrian era is the oldest and longest era in the geological time scale. Therefore, the correct choice is Cenozoic.

Which period is known for the mass extinction that wiped out the dinosaurs?

• Jurassic

• Triassic

• Permian

• Cretaceous

Answer explanation

The Cretaceous period is known for the mass extinction event that caused the extinction of dinosaurs. This period, which occurred approximately 66 million years ago, marked the end of the Mesozoic Era. The extinction was likely caused by a combination of factors, including a large asteroid impact and volcanic activity. The extinction event led to the rise of mammals and other new forms of life on Earth. The Cretaceous period is also known for the presence of iconic dinosaurs like Tyrannosaurus rex and Triceratops.

What is the name of the first major mass extinction in Earth's history?

• Ordovician-Silurian extinction

• Permian-Triassic extinction

• Cretaceous-Paleogene extinction

• Triassic-Jurassic extinction

Answer explanation

The first major mass extinction in Earth's history is known as the Ordovician-Silurian extinction. This extinction event occurred around 443 million years ago and resulted in the loss of approximately 85% of marine species. The extinction was likely caused by a combination of factors, including climate change, sea level fluctuations, and volcanic activity. The Ordovician-Silurian extinction is significant because it paved the way for the diversification of new species in the following periods.

Which mass extinction event is associated with the disappearance of the majority of marine species?

• Permian-Triassic extinction event

• Triassic-Jurassic extinction event

• Ordovician-Silurian extinction event

• Cretaceous-Paleogene extinction event

Answer explanation

The Permian-Triassic extinction event is associated with the disappearance of the majority of marine species. This event, also known as the Great Dying, was the most severe extinction event in Earth's history. It occurred approximately 252 million years ago and resulted in the extinction of about 96% of marine species. The Permian-Triassic extinction event was caused by a combination of volcanic activity, climate change, and anoxia (lack of oxygen) in the oceans. It marked the end of the Paleozoic Era and the beginning of the Mesozoic Era.

Which period is known for the mass extinction that wiped out 75% of species?

• Jurassic

• Cretaceous

• Permian

• Triassic

Answer explanation

The Permian period is known for a mass extinction event that wiped out 75% of species. This period was marked by significant environmental changes, including volcanic activity and climate change. The extinction event had a profound impact on the Earth's biodiversity, leading to the disappearance of many species. The Permian extinction is considered one of the most severe in Earth's history. It is important to note that the correct choice is 'Permian'.

What is the cause of the Permian-Triassic mass extinction event?

• Plate tectonics, deforestation, and solar radiation

• Meteorite impact, greenhouse effect, and overpopulation

• Asteroid impact, ocean acidification, and overhunting

• Volcanic activity, climate change, and anoxia

What are the four major divisions of the geological time scale?

• Era, Epoch, Period, and Age

• Eon, Era, Period, and Age

• Eon, Era, Epoch, and Age

• Eon, Era, Period, and Epoch