Question 1

Which hypothesis for the abiotic formation of organic molecules suggests that early Earth's atmosphere was a neutral atmosphere?

Accepted Answer

A)   The energy for this synthesis could have come from lightning and UV radiation.
B)   Some evidence suggests that the early atmosphere was made up primarily of nitrogen and carbon dioxide.
C)   Amino acids were found near volcanic eruption sites.
D)   Organic compounds were first produced in deep-sea hydrothermal vents. B

Question 2

The first genetic material on Earth was probably ________.

Accepted Answer

A)   DNA produced by reverse transcriptase from abiotically produced RNA
B)   DNA molecules whose information was transcribed to RNA and later translated in polypeptides
C)   self-replicating RNA molecules
D)   oligopeptides located within protocells C

Question 3

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 A

Question 4

Many species of snakes lay eggs. However, in the forests of northern Minnesota, where growing seasons are short, only live-bearing snake species are present. This trend toward species that have live births in a particular environment is an example of ________.

Accepted Answer

A)   an exaptation
B)   sexual selection
C)   species selection
D)   goal direction in evolution

Question 5

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 6

Why would gene duplication events, such as those seen in the Hox gene complex, set the stage for adaptive radiation?

Accepted Answer

A)   There are more copies of genes, meaning speciation had occurred by polyploidy.
B)   The original gene copy is the outgroup, and the new gene copies are the adaptive radiation.
C)   Without duplicated genes, species would be vulnerable to extinction.
D)   One copy of a gene can perform the original function, while other copies are available to take on new functions.

Question 7

How was early Earth from more than three billion years ago different from today's Earth? Unlike Earth today, early Earth ________.

Accepted Answer

A)   had an atmosphere rich in gases released from volcanic eruptions
B)   had an oxidizing atmosphere
C)   experienced little high-energy radiation from the sun
D)   had an atmosphere with significant quantities of ozone

Question 8

The following question is based on the observation that several dozen different proteins comprise the prokaryotic flagellum and its attachment to the prokaryotic cell, producing a highly complex structure.
If the complex protein assemblage of the prokaryotic flagellum arose by the same general processes as those of the complex eyes of molluscs (such as squids and octopi), then ________.

Accepted Answer

A)   natural selection cannot account for the rise of the prokaryotic flagellum
B)   ancestral versions of this protein assemblage were either less functional or had different functions than modern prokaryotic flagella
C)   neither eyes nor flagella could have arisen by evolution because both are too complex to have evolved
D)   the need for more complex structure must have driven evolution

Question 9

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from the air-breathing organ (a simple lung)of an ancestral fish is an example of

Accepted Answer

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

Question 10

If the half-life of carbon-14 is about 5,730 years, then a fossil that has 1/16 of the normal proportion of carbon-14 to carbon-12 should be about how many years old?

Accepted Answer

A)   2,800
B)   11,200
C)   16,800
D)   22,900

Question 11

Which of the following statements suggests natural selection as a mechanism in the evolution of ribozymes?

Accepted Answer

A)   Single-stranded RNA has many shapes.
B)   Replication of RNA is flawless.
C)   Some strands of RNA replicate less often.
D)   Some strands of RNA replicate more often and with more mutations.

Question 12

The following question refers to this hypothetical situation.
A female fly, full of fertilized eggs, is swept by high winds to an island far out to sea. She is the first fly to arrive on this island and the only fly to arrive in this way. Thousands of years later, her numerous offspring occupy the island, but none of them resembles her. There are, instead, several species, each of which eats only a certain type of food. None of the species can fly, and their balancing organs (halteres)are now used in courtship displays. The male members of each species bear modified halteres that are unique in appearance to their species. Females bear vestigial halteres. The ranges of all of the daughter species overlap.
In each fly species, the entire body segment that gave rise to the original flight wings is missing. The mutation(s)that led to the flightless condition could have ________.

Accepted Answer

A)   duplicated all of the Hox genes in these flies' genomes
B)   resulted in paedomorphosis
C)   altered the expression of a Hox gene
D)   originated in another species

Question 13

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 14

The following question refers to this hypothetical situation.
A female fly, full of fertilized eggs, is swept by high winds to an island far out to sea. She is the first fly to arrive on this island and the only fly to arrive in this way. Thousands of years later, her numerous offspring occupy the island, but none of them resembles her. There are, instead, several species, each of which eats only a certain type of food. None of the species can fly and their balancing organs (halteres)are now used in courtship displays. The male members of each species bear modified halteres that are unique in appearance to their species. Females bear vestigial halteres. The ranges of all of the daughter species overlap.
Which of these fly organs, as they exist in the description, best illustrates an exaptation?

Accepted Answer

A)   the vestigial halteres
B)   the halteres
C)   the mouthparts
D)   the eggs

Question 15

Which of the following is a defining characteristic that all protocells had in common?

Accepted Answer

A)   the ability to synthesize enzymes
B)   a surrounding membrane or membrane-like structure
C)   RNA genes
D)   the ability to replicate RNA

Question 16

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 17

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 18

Bagworm moth caterpillars feed on evergreens and carry a silken case or bag around with them in which they eventually pupate. Adult female bagworm moths are larval in appearance; they lack the wings and other structures of the adult male and instead retain the appearance of a caterpillar even though they are sexually mature and can lay eggs within the bag. This is a good example of ________.

Accepted Answer

A)   allometric growth
B)   paedomorphosis
C)   sympatric speciation
D)   adaptive radiation

Question 19

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 20

How does continental drift explain the uniqueness of Australian fauna?

Accepted Answer

A)   Marsupials fill the ecological niche as eutherians on other continents.
B)   Fossil evidence suggests that marsupials originated in Asia and reached Australia via South America.
C)   The subsequent separation of the southern continents formed an island of marsupials.
D)   In Australia, marsupials diversified, and eutherians became extinct.

Exam 25: The History of Life on Earth