Biological Diversity Quiz

How is a species defined?

• A group of organisms that can fly

• A group of organisms that is distinct from other groups in morphology, physiology, or biochemical properties

• A group of organisms that live in water

• A group of organisms that are all mammals

What percentage of species that have ever lived on Earth are now extinct?

• 50%

• 75%

• 99.9%

• 25%

What role do 'quiet' periods in the geologic record play in estimating extinction rates?

• They help estimate 'background' extinction rates

• They show the number of species that have evolved

• They indicate periods of rapid species growth

• They demonstrate the impact of human activity

What is the main focus of the document?

• The diversity and extinction of species on Earth

• The growth of human populations

• The development of new technologies

• The history of the Earth

What is the relationship between species extinction and human activity?

• Human activity has no effect on species extinction

• Human activity has accelerated species extinction

• Human activity has decreased species extinction

• Human activity has stabilized species extinction

What is the role of morphology in defining a species?

• It is unrelated to species definition

• It helps distinguish a species from other groups

• It is the only factor in species definition

• It is less important than physiology

Why is it difficult to determine the 'background' rate of extinction?

• Because it requires advanced technology

• Because it involves periods with no massive environmental upheaval

• Because it is constantly changing

• Because it is not scientifically important

Which species are mentioned as endangered and may go extinct if trends are not reversed?

• American bison, peregrine falcon

• Bengal tiger, snow leopard

• Bald eagle, California condor

• West Indian Manatee, peregrine falcon

What can the extinction of keystone species cause?

• Increase in biodiversity

• Cascade of extinction of dependent species

• Stabilization of ecosystems

• Growth in population

What does the overall rate of species extinction indicate?

• Increase in land area

• Decrease in biological diversity

• Improvement in air quality

• Stability of water resources