Chapter 25 The history of life on Earth

What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth? 1. origin of mitochondria 2. origin of multicellular eukaryotes 3. origin of chloroplasts 4. origin of cyanobacteria 5. origin of fungal-plant symbioses

4, 1, 3, 2, 5

Which listing of geological periods is in the correct order, from oldest to most recent?

Cambrian, Devonian, Permian, Cretaceous

According to the theory of seafloor spreading, oceanic islands, such as the Hawaiian Islands, form as oceanic crustal plates move over a stationary "hot spot" in the mantle. Currently, the big island of Hawaii is thought to be over a hot spot, which is why it is the only one of the seven large islands that has active volcanoes. What should be true of the island of Hawaii? I) Scientists in search of ongoing speciation events are more likely to find them here than on the other six large islands. II) Its species should be more closely related to those of nearer islands than to those of farther islands. III) It should have a rich fossil record of terrestrial organisms. IV) It should have species that are not found anywhere else on Earth. V) On average, it should have fewer species per-unit surface area than the other six islands.

I, II, IV and V

Which of the following characteristics are expected in the first animals to have colonized land? I) They were probably herbivores (ate photosynthesizers). II) They were tetrapods and not invertebrates. III) They had the ability to resist dehydration. IV) They had lobe-finned fishes as ancestors. V) They were invertebrates and not tetrapods.

I, III and V

Which factor most likely caused animals and plants in India to differ greatly from species in nearby southeast Asia?

India was a separate continent until 45 million years ago.

How does continental drift explain the uniqueness of Australian fauna?

The break-up of Pangea and subsequent separation of the southern continents isolated marsupials on Australia.

Why are fossils considered to be an incomplete record of evolution?

The fossil record is biased for organisms that had hard shells and skeletons.

Which of the following organisms would be most likely to form a fossil?

a common squirrel

Upon being formed, oceanic islands, such as the Hawaiian Islands, should feature what characteristic, leading to which phenomenon?

a variety of empty ecological niches, leading to adaptive radiation

Which of the following showed their greatest diversity during the Mesozoic era but were a small, less diverse group during the Paleozoic era?

fungi

What is the most accurate method used to measure the age of a fossil?

radiometric dating