Pre-Test

Chapter 26: The Tree of Life: An Introduction to Biological Diversity

Pre-Test

1 .

The oldest fossils usually _____. (Concept 26.1

contain more radioactive isotopes than younger fossils

are found in the deepest strata

have the longest half-lives

are found above younger fossils

are found in sediments from the Cenozoic era

2 .

Pangaea _____. (Concept 26.1

) [Hint]

was a land mass that broke up, forming the present-day continents

is the idea that all life on Earth is related

was an animal common in ancient seas but is now extinct

is the evolutionary history of a species, family, or phylum

is the theory that crustal plates can move relative to one another

3 .

Experiments in which electricity was discharged into a vessel containing hydrogen gas, water vapor, methane, and ammonia were conducted by _______. Their results support Oparin's theory on the origin of life. (Concept 26.2

) [Hint]

Miller

Watson and Crick

Darwin

Meselson and Stahl

Pasteur

4 .

Clay particles may have played an important role in the origin of life because _____. (Concept 26.2

) [Hint]

growing bacterial colonies can leave clay deposits

early life-forms probably ate clay

clay particles are a suitable template for the polymerization of simple organic molecules

clay is an important abiotic nutrient reservoir

clay provided shelter from UV radiation and ocean currents and provided a protected environment in which the first organisms evolved

5 .

Earth probably formed _____ years ago, and the first life evolved as early as _____ years ago. (Concept 26.3

) [Hint]

4.5 billion years ago ... 3.9 billion years ago

3.9 million years ago ... 2.0 billion years ago

6,000 years ago ... 6,000 years ago

10 billion years ago ... 4.5 billion years ago

none of the above

6 .

The earliest organisms were most likely ______. (Concept 26.3

) [Hint]

eukaryotic

prokaryotic

protobionts

multicellular

animals

7 .

Which of the following was probably not present in large amounts in the atmosphere at the time life is thought to have originated? (Concept 26.3

) [Hint]

water

nitrogen gas

carbon monoxide

oxygen gas

carbon dioxide

8 .

The atmosphere of early Earth probably contained no O₂ until the emergence of organisms that _____. (Concept 26.3

) [Hint]

used hydrogen sulfide as an energy source

were chemoautotrophic

used water as a hydrogen source for photosynthesis

were oxygen respiring

did none of these

9 .

Eukaryotic cells probably arose through _____. (Concept 26.4

) [Hint]

colonial aggregations of bacteria

associations between different prokaryotes

colonial aggregations of protists

direct descent from protobionts

incomplete bacterial fission

10 .

Until about 500 million years ago, all living things were _____. (Concept 26.5

) [Hint]

asexual

autotrophic

aquatic

prokaryotic

unicellular