Unit 9 Test - Evolution

According to the above timeline, what was the earliest form of multicellular life on Earth?

• fish

• invertebrates (soft-bodied organisms)

• land plants

• reptiles

Which was most likely a consequence of the breakup of the super-continent Pangea on the evolution of life on Earth?

• Populations of animals separated by the breakup of Pangea

  probably adapted to new environments and evolved into new species.

• Continental drift could rapidly change local climates, driving species to extinction.

• Populations of animals separated by the breakup of Pangea probably remained exactly the same over time.

• Continental drift could rapidly change local climates, triggering

  the evolution of new species.

Fossil evidence shows that photosynthetic bacteria (blue-green algae) were thriving as long as 3.5 billion years ago. Integrating this evidence and your own knowledge of algae, identify the most significant effect these organisms had on the ecosystem of the planet as a whole.

• Algae get energy from inorganic compounds such as hydrogen sulfide, so they could survive in places like hydrothermal vents at the ocean floor.

• Photosynthetic bacteria were among the first cells adapted as predators, so they spurred co-evolution among their prey in an early “arms race.”

• Blue-green algae were some of the first photosynthetic prokaryotes. The oxygen they produced accumulated in the earth’s atmosphere.

• Photosynthetic bacteria were the first eukaryotic cells. They harbored smaller prokaryotes that evolved into mitochondria and chloroplasts.

What was the significance of the Cambrian explosion to the evolution of life on Earth?

• It was a mass extinction during which nearly 90% of marine species were lost.

• It provides evidence to support the model of punctuated equilibrium and it led to a rapid diversification of the ancestors of most major animal groups.

• It was caused by tectonic instability, resulting in an eruption of multiple volcanoes.

• It was the event in which life began and led to the slow and steady appearance of new species throughout geologic time.

Which term best describes the structures shown in the illustration to the right?

• homologous

• analogous

• heterologous

• vestigial

Which of the following is a correct statement about the relationship between natural selection and evolution?

• Natural selection results from evolution.

• Natural selection includes evolution as a part of it.

• Natural selection is one mechanism of evolution.

• Natural selection and evolution are the same thing.

How do fossils demonstrate evidence of evolution?

• They show that ancient species share similarities with species now on Earth.

• They show similarities in DNA sequences between extinct organisms and modern ones.

• They are the only source of evidence of natural selection.

• Fossils reveal that many species have remained unchanged for millions of years.

Which of the following is the explanation of why bird wings and reptile forelegs are evidence of evolution?

• Similar functions point to a common ancestor.

• Analogous structures indicate a common ancestor.

• Vestigial structures point to a common ancestor.

• Homologous structures indicate a common ancestor.

Two populations become reproductively isolated. Which of the following is the best description of that phenomenon?

• speciation

• overproduction

• adaptation

• natural selection

Chloroplasts and mitochondria are both thought to have evolved through the process of

• photosynthesis

• cellular respiration

• chemical reactions

• endosymbiosis