Biology 2107                          Test  #1                    Spring, 2023



Name: __________________________                         ID#: ______________________



Section 1a (30 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 other 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



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 LESS 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.   Why do you think that the first organisms on the earth might have been anaerobic?


A.        Because you don’t need a nucleus to grow anaerobically,

B.        The first eukaryotic cells only emerged around 2.7 billion years ago (bya),

C.        Because there was little oxygen around at that time,  ~4.2 bya.

D.        Even though 600 mya, oxygen levels in the atmosphere were considerable, evolution of aerobic cells is more complex.

E.        Difficult to say, perhaps because mitochondria had not evolved yet.



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.   According to the arguments detailed in the class, thus far, which of the following is NOT a cause of change in the genetic structure of a given population?


A.     Mutation

B.     Gene flow

C.     Genetic drift

D.     Mitotic cell division

E.     Natural selection


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.   The average eukaryotic 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 eukaryote (other than human)  by its latin name  __________________   __________________,   What is it’s Genus? ___________________   2pts



Section 1b (19 pts.)

Please answer the following questions either using short, concise answers, or by explaining why you made appropriate changes to a figure -again using short, concise explanations.


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___ 


18.     Label the different phases in the Figure below, as it relates to one of the cellular activities mentioned in the previous question.



1.  ___S -phase_____         2.  ___Cell Division /Mitosis_____            3. ___Centromere____   



 (a)   (3 pts) Given the available possibilities, please correctly label the various items indicated by numbers in the above figure (potentially up to 1pt each correct label).


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


A.     Gap 2

B.     Gap 1

C.     Ataphase

D.     Anaphase

E.     S-Prophase


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

Gene flow,                           Mutualism,                                       Genetic Drift,          Gene Pool

Random Drift,                     Non-Darwinian Selection             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 (29 pts)


Please answer the following questions either using short, concise answers, or by explaining why you made appropriate changes that you have to any figure -again using short, concise explanations.




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


             Allopatric speciation occurs when a population of organisms becomes separated or isolated from their main group by some form of physical/geographic barrier. Over time, the allele frequency in the new group, which used to be homogenous across the individuals, becomes subject to changes via natural selection due to of pressure from differences in predators, climate, competitors and resources. eg. Polar Bears.  Sympatric speciation happens in a population without any geographic isolation.  eg. Hawthorne /apple fruitflies in NY




2.2. (6 pts.)  In another 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.) List three quite distinct differences between “prokaryotes” and eukaryotes.


Presence of Nucleus (Gram Negative bacteria DO have an organelle -the periplasmic space), Major Size, Circular vs Linear chromosome, peptidoglycan cell walls,

Singular RNA polymerases, presence vs absence of introns…

  Circular vs. Linear chromosome



2.4a. (3 pts.) Give one similarity between prokaryotes and eukaryotes, which might indicate some evolutionary realtionship


   ____Cell membrane, L-amino acids and D- sugars, universal code, Central Dogma _______________





2.5 . (8 pts.) In the Figure below, not knowing the fundamentals of potential evolutionary constraints on populations,

the artist has made more than a couple of fundamental mistakes.  Having taken Biol2107, however, with a little bit of care

and an eye for detail you are easily able to recognize these mistakes.

So, please circle each mistake  (1pt each) and then in the space provided below

the figure explain why you circled what you did. (1 pt each).




Why?___Directional selection misidentified__________________________________







Why?___Stabilizing Selection misidentified _________________________________







Why?____Lizards in the 3rd figure have been rearranged such that they would not give


rise to the selection described_   __________________________________________________







Why?____”genotypes” should be “phenotypes”_______________________________