Question 1

What concept explains the evolution of complex eyes?

Accepted Answer

A)  Complex eyes evolved through a series of steps that benefited the eyes. 
B)  Mollusc eyes evolved from a different ancestor than vertebrate eyes. 
C)  Through evolutionary history, eyes lose function of vision. 
D)  Mollusc eye's evolution was dependent on vertebrate eye evolution.

Question 2

Use the following information to answer the question.
A sediment core is removed from the floor of an inland sea. The sea has been in existence, off and on, throughout the entire time that terrestrial life has existed. Researchers wish to locate and study the terrestrial organisms fossilized in this core. The core is illustrated as a vertical column, with the top of the column representing the most recent strata and the bottom representing the time when land was first colonized by life.

If arrows indicate locations in the column where fossils of a particular type (see key) first appear, then which core in the figure above has the most accurate arrangement of fossils?

Accepted Answer

A)  core A 
B)  core B 
C)  core C 
D)  core D

Question 3

You are the lucky student of a wacky professor who develops a time machine. He asks if you will test it with him. You get in, and there is an immediate glitch-the date readout fails so that when you land, you are not sure what era you are in. As your time machine lands, you see an unusual landscape before you. As you open the door, you realize you cannot breathe. You quickly shut the door, realizing you are in the ________.

Accepted Answer

A)  Archaean eon 
B)  Cambrian period 
C)  Cenozoic era 
D)  Mesozoic era

Question 4

Use the following information to answer the question.
A sediment core is removed from the floor of an inland sea. The sea has been in existence, off and on, throughout the entire time that terrestrial life has existed. Researchers wish to locate and study the terrestrial organisms fossilized in this core. The core is illustrated as a vertical column, with the top of the column representing the most recent strata and the bottom representing the time when land was first colonized by life.

To assign absolute dates to fossils in this sediment core, it would be most helpful if ________.

Accepted Answer

A)  you knew the order in which the fossils occurred 
B)  the sediments had not been affected by underwater currents during their deposition 
C)  volcanic ash layers were regularly interspersed between the sedimentary strata 
D)  fossils throughout the column were equally spaced apart

Question 5

Endosymbiosis is an evolutionary theory that explains the origin of eukaryotes and suggests a specific order in which this might have occurred. Ancestral cells engulfed and then began to use the metabolic processes of the smaller cells. Based on shared-core processes and features, which statement most accurately describes the order, the theory, and the evolutionary implications for all organisms within domain Eukarya?

Accepted Answer

A)  Ancestral heterotrophic eukaryotes most likely engulfed both a heterotrophic and an autotrophic prokaryote, whereas ancestral photosynthetic eukaryotes probably provided the host cell for the first mitochondria. Over time, natural selection favored these relationships, and these cells became ancestors of all eukaryotes. 
B)  All ancestral eukaryotes would have most likely consumed a nucleus-like prokaryote that eventually became the eukaryotic nucleus. These new eukaryotic cells would have had an advantage over prokaryotic cells by acquiring a nuclear command center for regulating cellular activities. 
C)  As carbon dioxide levels were increasing over time, natural selection would have favored organisms that acquired a photosynthetic prokaryote to convert carbon dioxide into sugars. These would have likely been the first eukaryotic cells. These ancestral cells engulfed mitochondria-like prokaryotes, which would have provided an even greater advantage for cells in this environment. 
D)  As Earth was becoming more aerobic, mitochondria would have provided an advantage to host cells by converting "toxic" oxygen into energy for heterotrophic cells. Since mitochondria are found in all eukaryotes, these combinations likely evolved first. Photosynthetic eukaryotes probably acquired an autotrophic prokaryote, which developed an advantageous symbiotic relationship with the host cell.

Question 6

What major innovations of the three radiations was associated with defying gravity to facilitate life on land?

Accepted Answer

A)  stems 
B)  waxy covering 
C)  insect pollination 
D)  new sources of food

Question 7

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

Accepted Answer

A)  mass extinctions, leading to bottleneck effect 
B)  major evolutionary innovations, leading to rafting to nearby continents 
C)  a variety of empty ecological niches, leading to adaptive radiation 
D)  adaptive radiation, leading to founder effect

Question 8

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

Accepted Answer

A)  The climates of the two regions are similar. 
B)  India is in the process of separating from the rest of Asia. 
C)  Life in India was wiped out by ancient volcanic eruptions. 
D)  India was a separate continent until 45 million years ago.

Question 9

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

Accepted Answer

A)  gymnosperms 
B)  fungi 
C)  flowering plants 
D)  mammals

Question 10

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

Accepted Answer

A)  The fossil record shows changes in kinds of organisms that lived on earth. 
B)  The fossil record shows that many animals are extinct. 
C)  The fossil record is biased for organisms that had hard shells and skeletons. 
D)  Fossils document how new organisms come from preexisting organisms.

Question 11

The duplication of homeotic (Hox) genes has been significant in the evolution of animals because it ________.

Accepted Answer

A)  permitted the evolution of novel forms 
B)  caused the extinction of major groups 
C)  reduced morphological diversity into simpler forms of life 
D)  allowed animals to survive on significantly fewer calories

Question 12

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped make possible the evolution of the tetrapod limb. This type of change is illustrative of

Accepted Answer

A)  the influence of environment on development. 
B)  paedomorphosis. 
C)  a change in a developmental gene or in its regulation that altered the spatial organization of body parts. 
D)  heterochrony.

Question 13

Refer to the following information to answer the question.
Fossils of Lystrosaurus, a dicynodont therapsid, are most common in parts of modern-day South America, South Africa, Madagascar, India, South Australia, and Antarctica. The animal apparently lived in arid regions and was mostly herbivorous. It originated during the mid-Permian period, survived the Permian extinction, and dwindled by the late Triassic, though there is evidence of a relict population in Australia during the Cretaceous period. Some dicynodonts had two large tusks, extending down from their upper jaws. The tusks were not used for food gathering, and in some species were limited to males. Food was gathered using an otherwise toothless beak. Judging from the fossil record in sedimentary rocks, these pig-sized organisms were the most common mammal-like reptiles of the Permian.
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

Accepted Answer

A)  4, 3, 2, 1, 5 
B)  4, 1, 2, 3, 5 
C)  4, 1, 3, 2, 5 
D)  4, 3, 1, 5, 2

Question 14

If one organ is an exaptation of another organ, then these two organs ________.

Accepted Answer

A)  are homologous 
B)  are undergoing convergent evolution 
C)  are found in the same species 
D)  have the same function

Question 15

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of ________.

Accepted Answer

A)  exaptation 
B)  changes in Hox gene expression 
C)  paedomorphosis 
D)  adaptive radiation

Question 16

Hawaii is the most southeastern of the seven largest islands and is also closest to the seafloor spreading center from which the Pacific plate originates, which lies about 5,600 km farther to the southeast. Assuming equal sedimentation rates, what should be the location of the thickest sediment layer and thus the area with the greatest diversity of fossils above the oceanic crust?

Accepted Answer

A)  between the island of Hawaii and the seafloor spreading center 
B)  around the base of the island of Hawaii 
C)  around the base of Kauai, the oldest of the large Hawaiian islands 
D)  where the islands are most concentrated (highest number of islands per unit surface area)

Question 17

What adaptions by mammals helped their adaptive radiation after extinction of terrestrial dinosaurs?

Accepted Answer

A)  nocturnal vision 
B)  small size 
C)  increase in diversity 
D)  outcompeting for food

Question 18

The oxygen revolution changed Earth's environment dramatically. Which of the following took advantage of the presence of free oxygen in the oceans and atmosphere?

Accepted Answer

A)  the evolution of cellular respiration, which used oxygen to help harvest energy from organic molecules 
B)  the persistence of some animal groups in anaerobic habitats 
C)  the evolution of photosynthetic pigments that protected early algae from the corrosive effects of oxygen 
D)  the evolution of chloroplasts after early protists incorporated photosynthetic cyanobacteria

Question 19

Adaptive radiations can be a direct consequence of three of the following four factors. Select the exception.

Accepted Answer

A)  vacant ecological niches 
B)  genetic drift 
C)  colonization of an isolated region that contains suitable habitat and few competitor species 
D)  evolutionary innovation

Exam 25: The History of Life on Earth