Question 1

Which group of tetrapods had the first examples of specialized teeth?

Accepted Answer

A)   synapsids
B)   therapsids
C)   early cynodonts
D)   later cynodonts B

Question 2

For purposes of differentiation, what is the unique feature of the jaw fossils of nonmammalian tetrapods?

Accepted Answer

A)   Lower jaw and upper jaws hinge between the same bones.
B)   Lower jaw is composed of several bones.
C)   There are three bones in the middle ear.
D)   Teeth are differentiated for function. B

Question 3

One explanation for the evolution of insect wings suggests that wings began as lateral extensions of the body that were used as heat dissipaters for thermoregulation. When they had become sufficiently large, these extensions became useful for gliding through the air, and selection later refined them as flight-producing wings. If this hypothesis is correct, modern insect wings could best be described as

Accepted Answer

A)   adaptations.
B)   mutations.
C)   exaptations.
D)   isolating mechanisms. C

Question 4

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 5

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 6

Adaptive radiation

Accepted Answer

A)   reduces the size of prosperous ecological communities.
B)   increases extinction rates.
C)   allows new species to occupy different habitats.
D)   observes trends in the fossil record.

Question 7

A researcher discovers a fossil of what appears to be one of the oldest-known multicellular organisms. The researcher could estimate the age of this fossil based on

Accepted Answer

A)   the amount of uranium-238 in the fossil.
B)   the amount of carbon-14 in the fossil.
C)   the amount of uranium-238 in volcanic layers surrounding the fossil.
D)   the amount of carbon-14 in volcanic layers surrounding the fossil.

Question 8

Exaptations

Accepted Answer

A)   imply that a structure evolves in anticipation of use.
B)   evolve in one environment but are used for another function.
C)   process new forms by modifying existing forms.
D)   trend toward larger body size.

Question 9

Which of the following is a biological cause of extinctions?

Accepted Answer

A)   habitat destruction
B)   change in environment temperature
C)   ocean anoxia
D)   origin of new species

Question 10

A difficulty in presenting evidence for a sixth mass extinction is

Accepted Answer

A)   that tropical rain forests harbor many unknown species.
B)   that species numbers are declining because of habitat loss.
C)   introduction of new species.
D)   increased global temperatures.

Question 11

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 12

The first terrestrial organisms probably were considered which of the following?
1) burrowers
2) photosynthetic
3) multicellular
4) prokaryotes
5) eukaryotes
6) plants and their associated fungi

Accepted Answer

A)   2 and 4
B)   3 and 5
C)   1, 3, and 5
D)   2, 3, and 6

Question 13

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

Accepted Answer

A)   The species became separated by convergent evolution.
B)   The climates of the two regions are similar.
C)   India is in the process of separating from the rest of Asia.
D)   India was a separate continent until 45 million years ago.

Question 14

The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that

Accepted Answer

A)   a larger volume-to-surface area ratio is beneficial to all mammals.
B)   an unseen guiding force is at work.
C)   evolution always tends toward increased complexity or increased size.
D)   in particular environments, similar adaptations can be beneficial in more than one species.

Question 15

The evolution of mammals from early tetrapods

Accepted Answer

A)   is well documented by a series of transitional fossils.
B)   involves specialization in teeth.
C)   involves changes in the temporal fenestra of the skull.
D)   is an example of macroevolution.

Question 16

Please use the following information to answer the question(s) below.
Figure 23.1 represents a cross section of the seafloor through a mid-ocean rift valley, with alternating patches of black and white indicating seafloor with reversed magnetic polarities. At the arrow labeled I (the rift valley), the igneous rock of the seafloor is so young that it can be accurately dated using carbon-14 dating. At the arrow labeled III, however, the igneous rock is about 1 million years old, and potassium-40 dating is typically used to date such rocks. Note: The horizontal arrows indicate the direction of seafloor spreading, away from the rift valley.  Figure 23.1
- Figure 23.2
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 in Figure 23.2 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. Assuming the existence of fossilized markers for each of the following chemicals, what is the sequence in which they should be found in this sediment core, working from ancient sediments to recent sediments?
1) chitin coupled with protein
2) chlorophyll
3) bone
4) cellulose

Accepted Answer

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

Question 17

Adaptive radiations can be a direct consequence of four of the following five 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

Question 18

What is true of the fossil record of mammalian origins?

Accepted Answer

A)   It is a good example of punctuated equilibrium.
B)   It shows that mammals and birds evolved from the same kind of dinosaur.
C)   It includes transitional forms with progressively specialized teeth.
D)   It indicates that mammals and dinosaurs did not overlap in geologic time.

Question 19

The following question(s) refer 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, for their flight wings are absent, and their balancing organs (in other words, 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 current fly populations, best fits the description of an exaptation?

Accepted Answer

A)   wings
B)   balancing organs
C)   mouthparts
D)   thoraxes
E)   walking appendages

Question 20

Please use the following information to answer the question(s) below.
All animals with eyes or eyespots that have been studied so far share a gene in common. When mutated, the gene Pax-6 causes lack of eyes in fruit flies, tiny eyes in mice, and missing irises (and other eye parts) in humans. The sequence of Pax-6 in humans and mice is identical. There are so few sequence differences with fruit fly Pax-6 that the human/mouse version can cause eye formation in eyeless fruit flies, even though vertebrates and invertebrates last shared a common ancestor more than 500 million years ago.
-Scientists, looking at the range of beak shapes and sizes across different finch species, observed that the thicker beak expressed a gene known as BMP4 early in development. To verify that the BMP4 gene itself could trigger the growth of bigger beaks, researchers increased the production of BMP4 in the developing beaks of chicken embryos. Which of the following results would explain why BMP4-treated chicks began growing wider, taller beaks?

Accepted Answer

A)   Change to the genome induces radical changes in form.
B)   New genes arise every time a new species arises.
C)   Development cannot change morphology.
D)   BMP4 is a homeotic gene.

Exam 23: Broad Patterns of Evolution