Biology 2107                      Test  #1                           Spring, 2020



Name: __________________________                         ID#: ______________________



Section 1a (32 pts.)

Please circle the letters that precede the most appropriate answer(s) to the question asked.  Circling more than one letter in answering any given question will count against you. 



1.     Evolution of species on Earth


A.     has stopped.

B.     occurred only in the distant past.

C.     only occurred after the Cambrian explosion.

D.     has occurred throughout Life’s history and is still under way.

E.     None of the above


2.         Over MOST of its history, the climate on Earth has been:


A.     about the same as it is today.

B.     considerably cooler than it is today.

C.     considerably warmer than it is today.

D.     unknown; we have no information about earth’s climate in the past.

E.     much more variable on an annual basis.


3.     A hinny or a mule is an example of :


A.        A consequence of a prezygotic barrier.

B.        A consequence of a postsynaptic barrier.

C.        A consequence of a postzygotic barrier.

D.        A consequence of postsynaptic rigor.

E.        A wonderful and friendly four legged rodent.

F.        A consequence of spatial isolation resulting in gametic interactions.

G.       A consequence of hybrid vigor.


4.      The biological species concept (BSC) states that:


A.        species are groups of potentially interbreeding natural populations which are reproductively available to all other such groups.

B.        species are groups of actually interbreeding populations which are sometimes reproductively isolated from other such groups.

C.        species are groups of actually, or potentially interbreeding natural populations which are reproductively isolated from other such groups.

D.     species are groups of actively interbreeding natural populations, which are reproductively similar to other such groups.

E.        species are groups of potentially interbreeding subpopulations, which are reproductively isolated from other such groups.



5.      The modern polar bear species has potentially evolved from ancestral species of bears that populated southern Alaska, but which became separated by glaciers from bear populations in the rest of North America.  The general term for this type of event would be called a(n):


A.     allopatric speciation.

B.     temporal isolation.

C.     mechanical isolation.

D.     sympatric speciation.

E.     glacial speciation

F.     sympatric specialization


6.      Consider the phylogeny below


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Species M has green toes, while species L has red toes. 

If Species H and K have green toes, what can you conclude about the evolution of red toes from this tree?


A.     It occurred in the common ancestor of M, H, K and L

B.     It occurred in the common ancestor of H, K and L

C.     It occurred in the lineage leading to L after that lineage diverged from the common ancestor

         of H and K

D.     It is a monophyletic trait.

E.     It is a paramorphic trait


7.      In which phase of a cell’s cycle is the majority of its DNA replicated ?


A.     Prophase

B.     Interphase

C.     Anaphase

D.     Prometaphase

E.     Gap1 phase

F.     Interkinesis


8.      What is the generic “currency” of energy for most living organisms?


A.        Oxygen

B.        Water

C.        ATP

D.        Vitamin B12

E.        OTU

F.        AMP


9.      What kind of selection is occurring if both the smallest and the largest individuals contribute relatively more offspring to the next generation than those closer to the average height?


A.     Disruptive selection

B.     Stabilizing selection

C.     Disruptive selection and stabilizing selection

D.     Directional selection

E.     Directional selection and stabilizing selection



10.   Evolution -when taken to its logical conclusion- would suggest that:


A.      All living organisms share a common heritage.

B.      Shared traits always suggest a shared heritage.

C.      Mass extinction of species is a necessary consequence of evolutionary change.

D.      All of the above.

E.      A and B only. 



11.   According to geological data and fossil records (that we reviewed in an early lecture), which one of the following statements do you consider to be most likely?


A.        The temperature of the earth has stayed relatively constant over the last million years,

B.        The first eukaryotic cells emerged around 16 million years ago (mya),

C.        Around 500 million years ago most of the earth’s continents were in the Southern hemisphere.

D.        Around 600 mya Oxygen levels in the atmosphere were twice the level that they are today

E.        Whales are direct descendents of the modern day wolf.

F.        Man is not responsible for any of the climatic changes that have occurred over the last century.


12.   The term “carrying capacity” refers to:


A.     The ability of animals -such as pandas- to hold or carry bamboo shoots.

A.        The limits of a population that are defined by its genetic variation.

B.        The number of genes within a given population.

C.        The maximal population size within a given environment.

D.        The number of obvious phenotypic traits that arise in a population.



13.   Which part of the eukaryotic chromosome is involved in formation of the kinetochores, which bind the spindle fibres:


A.        chromomere

B.        synaptonemal complex

C.        centrosome.

D.        centromere

E.        nucleolus

F.        centriole


14.   Which one of the following statements distinguishes a prokaryotic cell from a eukaryotic cell?


A.        The prokaryotic cell has a nucleus.

B.        The eukaryotic cell is often much smaller.

C.        The prokaryotic cell has at least one cell membrane.

D.        The prokaryotic cell is a single celled organism.        

E.        The eukaryotic cell has a nuclear membrane.


If  all statements above  are true then circle     “F”.   

If  all statements above  are not true then circle    “G”


15.   Nonadaptive mechanisms of evolutionary change are


A.        migration (gene flow), mutation and genetic drift.

B.        migration (gene flow), heterozygotic advantage and genetic drift.

C.        migration (gene flow), sexual selection and genetic drift.

D.        Mutation, sexual selection and genetic drift.

E.        Mutation, genetic drift and heterozygotic advantage




16.   The average bacterial cell is approximately:


A.        1.5 – 3 µm in length,

B.        1 - 5 nm in length.

C.        100-500 µm in length.

D.        1m in diameter.

E.        1mm in diameter.



Bonus: Name one bacterium __Escherichia________  ___coli______ , What is it’s Genus? __ Escherichia________ 



Section 1b (20 pts.)

In the next few answers, please insert the most appropriate word(s) (from the list of words given) into the spaces provided.


17.      (a)   (4 pts) Place the categories listed below in their correct order of hierarchy –according to Linnaean grouping  (you can go up or down –it doesn’t matter).


Domain,   Genus,     Kingdom,    Order,    Phylum,  Species ,    


___ Domain ____    ___ Kingdom ____    ____ Phylum ____    ___ Order ___  


____ Genus _____    ___ Species ___



(a)   (2 pts) Which category(ies)  is (are)  missing?


___Class___   ____Family___ 



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Centrosome,              Spindle fibers,           Kinetochore,             Ribosomes,               Chromatids,

                                                            Kinesin,                      Chromaphore            Centromere


 (a)   Given the available possibilities, please correctly label the various items indicated in the above figure (1pt each correct answer).


 (b)   (2 pts) Given your knowledge of Cell division, in which phase of Mitosis would the represented chromosome be found.


A.     Prophase

B.     Metaphase

C.     Ataphase

D.     Anaphase

E.     Meta-Prophase


19.      Allele Frequencies,               Aponymous Frequencies,               Phenotype,                Equanimity, 

Gene flow,                             Mutualism,                                         Genetic Drift,             Gene Pool

Non-Darwinian Selection     Random Drift,                                    Genetic toolkit,             Onomatoplasia,

Genetic Frequencies Commensalism.


(a).      (2 pts) The frequencies of the variant types of genes being present in a population are called _ Allele Frequencies _


 (b).     (2 pts) The _ Gene Pool __  is the sum total of genetic information in a population at any given moment. It includes every allele at every locus in every organism within that population.


 (c).     (2 pts) In a small population, small changes in the allele frequencies over time result from chance events and this is called

__ Genetic Drift ___.


20.      (2 pts)   Food,    Shelter, Genotype,   Disease,    Predation,  Genetic Drift     


 “Environmental limitations on a Population’s growth include: 


            ___ Food _____,   ___ Shelter ____,  ____ Disease ______,   ___ Predation ___ “


Section 2 (27 pts) Actually 33 pts


Please answer the following questions either using short, concise answers or by indicating appropriate changes in the figures that would  and using short, concise answers.


2.1 (6 pts.) Compare and contrast the terms “Allopatric” and “Sympatric” speciation events.  Give an example of one.


Allopatric speciation occurs in separate, non-overlapping geographical areas, in populations that are normally

separated by a significant geographic barrier

eg. Polar Bears from Alaskan Bears


Sympatric speciation occurs in populations while both continue to inhabit the same geographic location,

i.e no geographic barrier


eg. "black-bellied seed cracking finches of West Africa



2.2. (6 pts.)  In a movie that we all viewed in class, the professor suggested a number of critical events that may have lead up to the evolution of the mammalian eye.  Briefly explain/describe two of them.


Evolution of light -sensitive cells, that developed some 3D perspective (epitomized

by a “Cup-like’ organization), followed by limiting of light access by narrowing

the “aperture”, followed by the formation of see-through membranes over the aperture,

which can be converted into a “lens” by addition of excess fluid.




2.3. (6 pts.) Briefly discuss some of the differences between “Gram positive” and “Gram negative” bacteria.


   Fundamentally, Gram positive cells have a singular cell membrane surrounded by a very thick murein layer,

while Gram negative cells have two membranes, creating the “periplasmic space” (effectively an organelle)

in which there is a thin layer of “murein sheath” (peptidoglycan layer), which provides rigidity and strength to

the cell.

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2.4a. (6 pts.) List three quite distinct differences between prokaryotes and eukaryotes


   Murein sheath/layer, size, method of cell division, presence/absence of nucleus, presence/absence of

 multiple organelles etc


2.4b. (3 pts.) Give one similarity between prokaryotes and eukaryotes, which might indicate evolutionary relationships between the two.


 Both Prokaryotes and eukaryotes have membranes made of lipid bilayers, generally use similar building blocks (L-amino acids and D-sugars), RNA and DNA, shared  genetic code for protein synthesis,



2.5 - 2.6. In the following two questions (each being worth 3 pts) please indicate which of the two animals are evolutionarily more closely related to each other by circling the two appropriate pictures.  Then in the space provided, suggest a reason why you might think this to be so,





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Why ______________Both  mammals ____________________________ 1pt _____]




Why______Both  are chordates  Tunicates have a “notochord” in early development_____ 1pt __