What caused the iridium anomaly?

• an impacting asteroid or comet hit the Earth

• a volcanic eruption

• a supernova that exploded

Select all the pieces of evidence provided by Alvarez to support the impact theory.

• high iridium concentration

• fossils

• Shocked quartz grains

• excesive levels of plutonium

What is the significance of the iridium anomaly in the study of the extinction of dinosaurs?

• It indicates a decrease in volcanic activity.

• It suggests a change in oceanic temperatures.

• It provides evidence of an asteroid collision.

• It points to a rise in atmospheric carbon dioxide.

The fossil record is primarily based on the preservation of:

• a) Soft tissues

• b) Muscle fibers

• c) Bones and teeth

• d) Cell structures

Which of the following best describes the role of the fossil record in understanding the history of life on Earth?

• a) It provides a complete and continuous record of all extinct species.

• b) It offers insights into the evolution of specific organisms, but not broader patterns.

• c) It helps scientists understand the timing and relationships between different organisms.

• d) It is irrelevant to the study of Earth's history.

An asteroid collision with Earth is believed to have caused the mass extinction of dinosaurs, approximately:

• a) 10 million years ago

• b) 50 million years ago

• c) 66 million years ago

• d) 100 million years ago

The Chicxulub crater, believed to be linked to the extinction of dinosaurs, is located in:

• a) Australia

• b) Mexico

• c) Antarctica

• d) Canada

The impact of an asteroid collision can cause widespread destruction due to:

• a) Earthquakes

• b) Volcanic eruptions

• c) Tsunamis

• d) All of the above

Fossils are typically formed through a process called:

• a) Carbon dating

• b) Fossilization

• c) Radiometric decay

• d) Sedimentary deposition

The size of a crater formed by an asteroid impact depends on various factors, including the:

• a) Speed of the asteroid only

• b) Size of the asteroid only

• c) Speed and size of the asteroid

• d) Atmospheric conditions at the impact site