Midterm Exam - Principles of Biology (BIO 242) MAKEUP EXAM
Print your name, last name first on the scantron. Mark the most appropriate answer on your scantron.
If you make erasures, write "check#" and the number of the question on the bottom of your scantron.
Good luck. Questions are two points each (100 total points).
1. The modern synthesis of evolutionary thought combines the work of what two people to provide a
better understanding of how evolution works.
a. Darwin and Cuvier
c. Lamark and Hutton
e. Darwin and Wallace
b. Darwin and Lamark
d. Darwin and Mendel
2. Which one of the following does not reflect a view that was held by natural theologists in the mid
1700s?
a.
b.
c.
d.
diversity of life reflects the Creator’s master plan
the type and number of species change over time
the Earth was young (< 6,000 years)
species present is fixed and constant
3. Populations of a species of mammal are found exclusively in canyons in Arizona. While there are
several populations of this mammal species, they are typically separated by the distance between the
canyons. Members of one population migrate to another canyon and join the population currently
occupying that canyon, thereby changing the gene pool of the population. Changes in the gene pool
of a population in this manner is a result of
a. mutation
c. genetic drift
b. selection
d. gene flow
4. Evolutionary mechanisms act on which level of organization in the hierarchy of life?
a. genome
c. species
e. community
b. individual
d. population
5. True (A)/False (B): All disciplines of biology should be viewed and treated as related and
intertwined. The topics of each discipline are related and work cooperatively to develop a better
understanding of how life operates.
6. Many populations of elephant seals were reduced to extremely low numbers by over-hunting.
Conservation efforts have raised their numbers considerably, but this rescue effort has limited the
capacity of elephant seals to respond to environmental changes because their gene pool now contains
little genetic _____________ because the recovery was based on a small number of individuals.
a. homogeneity
c. flow
b. variability
d. mutability
7. What kind of selection is exerted on a population if both the smallest- and largest-sized individuals
contribute relatively fewer offspring to the next generation than individuals that are closer to the
average size of individuals in the population?
a. stabilizing selection
c. disruptive selection
b. directional selection
d. sexual selection
8. Which of the following is a true statement about Charles Darwin?
a. He was the first to suggest that living things can change, or evolve, over time
b. He based his theory on the inheritance of acquired characteristics
c. He worked out the principles of population genetics
d. He proposed natural selection as a mechanism of evolution
e. He was the first to realize that Earth is billions of years old
9. True (A)/False (B): A single terrestrial species has a geographic range that extends from the Florida
into central Canada and is found throughout this range. The relative fitness of all the possible
genotypes for a given trait critical to this species’ survival differs as a function of the environmental
conditions to which they are subjected within a given area.
10. Humans possess a postanal tail during their embryological development, but the tail is reabsorbed
later in development. Since the presence of a postanal tail is a characteristic of all members of
Phylum Chordata (amphioxus, tunicates, fish, birds, mammals, reptiles) and is a link to their common
ancestor, the presence of a postanal tail in humans is an example of a(n) ________ trait/characteristic.
a. acquired
c. derived
b. primitive
d. symplomorphic
11. Refer back to the species in question #3. A study was conducted to determine the relatedness
between the populations of this species. The study found that the populations now become
reproductively active at different times of the year so that individuals from different canyons can no
longer interbreed. This is likely an example of
a. directional selection
c. reproductive isolation
b. sympathetic speciation
d. genetic drift
12. The principle which states that prebiotic chemical processes should be evident in the biochemistry of
modern life, and which helps to establish a foundation for the development of hypotheses of the
origins of life, is the
a. principle of continuity
c. no-free-lunch principle
b. signature principle
d. prebiont principle
13. The earliest known fossils of any life-form on this planet date to around __________ years ago.
a. 3.5 billion
c. 575 million
b. 1.5 billion
d. 6 thousand
14. Glycolysis is the only metabolic pathway common to nearly all organisms. To scientists, this suggests
that it
a. evolved very early in the history of life.
b. was first seen in early eukaryotes.
c. evolved very late in the history of life.
d. it must be very a complex process.
e. appeared rather recently in the evolution of life.
15. True (A)/False (B): It is unlikely that life could evolve from non-life today because organic
molecules present in the environment as free molecules today are rapidly consumed by tremendous
number of living organisms on the planet today.
16. The first form of life was probably a
a. autoheterotrophic prokaryote
c. chemoheterotrophic prokaryote
b. chemoheterotrophic eukaryote
d. photoautotrophic eukaryote
17. True (A)/False (B): Early life forms that were capable of synthesizing molecules that stored energy
would have no selective advantage over members of the same species that had to continually consume
organic molecules present in the environment for energy.
18. There are some bacteria that live in very inhospitable environments. They are capable of producing
their own organic molecules using inorganic compounds as an energy source. This mode of energy
acquisition is referred to as
a. photoautotrophy
c. chemoautotrophy
b. chemoheterotrophy
d. photoheterotrophy
19. Antiobiotics are often designed to act specifically on pathogenic and nonpathogenic bacteria with the
intent to not harm pathogenic bacteria. It is possible to accomplish this because antibiotics can be
designed to chemically distinguish between the ____________ of bacteria.
a. cytoplasm
c. DNA
b. cell wall
d. cell membrane – gave credit for
this also but B is most correct
20. The model for the origin of eukaryotes which hypothesizes that chloroplasts and mitochondria evolved
from small prokaryotes living within larger prokaryotes is the
a. endosymbiotic model
c. ectosymbiotic model
b. autogenous model
d. commensal model
21. Fungi perform which of the following functions biologically?
a. decomposers
c. symbionts
b. pathogens
d. all of the above
22. Which of the following is not evidence for the role of endosymbiosis in the origin of eukaryotes?
a. Chloroplasts have their own DNA
b. The inner membrane of mitochondria is similar to prokaryotic membranes
c. Mitochondria and chloroplasts are surrounded by two membranes
d. Mitochondria can function outside of the cell in which it was originally found
23. Although fungi evolution is not well understood, it is likely that they evolved from a(n) _____
ancestor.
a. protistan
c. plant
b. animal
d. they just appeared
24. The fact that there is evidence of increasing complexity in prokaryotes (e.g., multicellular specialization,
complex communities) are significant in the understanding of eukaryotic evolution because
a.
b.
c.
d.
multicellular organisms were the first eukaryotes
you would have to be complex to produce acritarchs
it provides an evolutionary link between prokaryotes and eukaryotes
none of the above
25. Which of the following is not an observation or inference on which natural selection is based?
a.
b.
c.
d.
there is heritable variation among individuals
poorly adapted organisms never leave offspring
there is a limited amount of resources available
individuals whose inherited characteristics best fit them to the environment will leave more
offspring
26. An essential attribute of the ancestor to eukaryotic organisms would be that the cells exhibit
a.
b.
c.
d.
some coordination and cooperation
function completely independently
show no specialization
b and c
27. True (A)/False (B): All members of Kingdom Fungi share the common feature that their body is
composed of string-like structures called hyphae and these are arranged in a mycelium.
28. True (A)/False (B): Changes in a species that are observed on several generations (a period of
perhaps 10 – 100 years) consists of observations on a geological time scale.
29. Lamark is often mistakenly ridiculed for the ideas he presented in his evolutionary theory, but a major
contribution of his work to future scientific was his recognition that
a. animals evolved from plants
c. fossils are formed from dead animals
b. acquired traits are inherited
d. organisms adapt to the environment
30. In the endosymbiotic model of eukaryotic evolution, the relationship between a large prokaryote that
contained one or more smaller heterotrophic prokaryotes within its cytoplasm is an example of ______
symbiotic relationship because both organisms benefit from the interaction.
a. competitive
c. mutualistic
b. commensalistic
d. parasitic
31. True (A)/False (B): An environment that is completely devoid of oxygen in the lake bottom would
be the ideal habitat for an obligate aerobic organism.
32. Archaea and Eukarya are likely to have shared a common ancestor because of similarities in the
cytoplasm and similarity in the eukaryote nucleus to the structure of the archaean
a. cell membrane
c. Golgi bodies
b. DNA
d. ribosomes
33. A key feature of the sporic life cycle of protistans is the presence of alternation of generation. This
feature is significant because it establishes an evolutionary link between protists and
a. plants
c. prokaryotes
b. animals
d. fungi
34. To Cuvier, the differences in fossil species between different rock strata were evidence for
a.
b.
c.
d.
e.
changes occurring as a result of cumulative but gradual processes
divine creation
evolution by natural selection
continental drift
local catastrophic events such as droughts and floods
35. An increase in the number of Hox genes present in animals has been proposed to explain the
evolution of
a. gene regulation
c. greater complexity in body forms
b. reproductive isolation
d. gene expression
36. The formation of cysts, such as those that envelope the cell of some protists, are a common strategy
among organisms as a means of avoiding
a. predation
c. precipitation
e. professors
b. drying
d. competition
37. Bullock's oriole and the Baltimore oriole are believed to be two closely related species, but could
they actually be the same species? The most effective way to answer this question would be to see
whether they
a. sing similar songs
c. live in the same areas
e. successfully interbreed
b. look alike
d. have the same number of chromosomes
38. The imperfect fungi were once placed in their own division/phylum because scientists had not been
able to determine how they
a. acquired nutrients
c. responded to stimuli
b. made symbiotic relationships
d. reproduced sexually
39. The endosymbiotic model of evolution was controversial initially because it proposed __________
which is opposition to the way ancestral lineages are viewed.
a. the divergence of two groups
c. the evolution of radically new traits
b. the convergence of two groups
d. evolution in absence of genetic change
40. Changes in the genetic makeup of a population over time best describes
a. catastrophism
c. evolution
b. Lamarkism
d. natural theology
41. A group of actually or potentially interbreeding individuals that are reproductively isolated from
other groups best describes the
a. morphological species concept
c. reproductive species concept
b. cohesion species concept
d. biological species concept
42. According to the Hardy-Weinberg theorem,
a. the genetic structure of a population should remain at equilibrium from one generation to
the next if five specific conditions are met
b. only natural selection will cause evolution
c. genetic drift, gene flow, mutations, and non-random matings do not occur in nature
d. none of the above
e. all of the above
43. True (A)/False (B): Prezygotic reproductive isolating mechanisms function to prevent the fusion of
gametes to form a fertilized egg (zygote) between individuals of different species.
44. Which of the following components is required for speciation to occur
a.
b.
c.
d.
e.
separation from main (original) species either physically or reproductively
different selection forces acting on each group
no interbreeding between groups
establishment of reproductive isolation
all of the above
45. True(A)/False (B): Natural selection always leads to the formation of new species.
46. A gene pool consists of
a. all the alleles exposed to natural selection
b. all the alleles in a population
c. the entire genome of an individual
d. the frequencies of all alleles for one gene in a population
47. True (A)/False (B): Genotype GG is the most fit until environmental conditions change and another
genotype becomes favored. If environmental conditions return to this prior state, genotype GG would
again be the most fit genotype.
48. Which of the following contributes substantially to the diversity of prokaryotes?
a. asexual reproduction
c. sexual reproduction
e. b and d
b. horizontal gene transfer
d. large genome
49. A critical aspect of sexual reproduction is the passage of genes from one generation to the next. For
this to be possible, ______________ molecules had to evolve.
a. replicator
c. ATP
b. metabolic
d. glucose
50. True (A)/False (B): When we refer to the evolution of eukaryotes from prokaryotes, what we actually
mean is that a single species of prokaryote started the process that lead to the evolution of eukaryotes
(not counting symbiotic prokaryotes).