SCI 135 - Fourth Exam Spring 2013


Links connect to relevant parts of the online book.





 On the line to the left, place the letter of the choice that best  answers the question.

Three Points Each.                  NOTE:  "e" answers are never the correct answer.




                        1.   Enzymes from the stomach stop working in the intestine because


_______                    a.   They aren’t needed there                      b.   They get inhibited

                                 c.   There is no oxygen there                      d.   The pH changes

                                 e.   Their contract does not allow the overtime



                        2.   Which comes closest to being universally used in biological systems?


_______                    a.  Ammonia                          b.  Oxygen                             c.  ATP

                                d.  Carbon dioxide                           e.  Slimy stuff



                        3. Which ability was probably critical to the original development of photosynthesis?


_______                    a.  Light sensing                                            b.  Predation

                                 c.  Independent movement                            d.  Aerobic respiration

                                 e.  The ability to hang around one place and not get really bored



                        4.   The beginnings of eukaryotes is very much tied to


_______                    a.   The heterotroph hypothesis                 b.  Colonialism

                                 c.  The endosymbiosis theory                    d.  Photosynthesis

                                                e.  What would want to be tied to that?



                        5.   Which term is specifically defined according to a human ability?

_______                    a.  Enzyme                 b.  Gene                      c.   Respiration

                                d.  Vitamin                             e.  Humor?



                        6.   The aerobic stage of respiration is approximately _______ times

                                                more efficient than the anaerobic stage.


_______                    a.  2                 b.  200                           c.  18                           d.  75

                                                e.  Ooo, he warned us about this one…




                        7.    Enzymes do their job by

_______                    a.  Transferring electrons

                                 b.  Lowering activation energy

                                 c.  Increasing acidity

                                 d.  All of the above

                                 e.  Just looking busy when the boss comes by




                        8.    Your sweet receptors will react to a broad number of different

                                                molecules.  This is an example of

_______                    a.  Low specificity                            b.   Multiple binding sites

                                 c.  Different gene activation              d.   Inhibition

                                                e.  How we really like sweets




                        9.  The Snowball Period probably most accelerated the evolution of

_______                    a.   Single-celled eukaryotes                      b.  Prokaryotes

                                c.  Animals                            d.   Plants                               e.  Elves




                        10.  Many ATPs are made in

_______                    a.  The Kreb Cycle                           b.   The Calvin Cycle

                                c.  Glycolysis                                    d.   The Electron Transport Chain

                                    e.  Of course, no one would name it “the ATP-makin’ step”




                        11.   Which part of a lipid can be broken down in respiration?

_______                    a.  Fatty acids                                    b.  Amino acids

                                 c.  Nucleic acids                                d.  Glycerol

                                                        e.  The breathy parts




                        12. The “plant problem” was associated with

_______                    a.  Hybridization events                              b.  The first living things

                                c.  Prepping proteins for analysis                 d.  Mass extinctions

                                                            e.   People who snort oregano





Answer any eight of the following questions for 4 Points Each.

            Note:  if you answer more than eight, only the first eight  will be corrected.

            You can get partial credit on these answers.

1.        What are two different initiating events that could “set off” a mass extinction?



2.    Mass extinctions can be initiated by many different events, but what always has to happen that ultimately brings about the extinctions?


3.        Describe, with some detail, how end-product inhibition works.


4.    What are the three levels, in order, of a typical food chain?
5.    What is panspermia?


6.   What are two of the main types of nitrogenous wastes?


7.  A feature of the fossil record is used to estimate when photosynthesis became widespread on the Earth.

What is



How would it

have been


8.   In general, what is coupled in coupled reactions?



9.   In a food chain, what ultimately happens to most of the -



10.  What are two different reasons why an enzyme might be irreversibly inhibited?


11.  The two likeliest staging areas from which aquatic organisms moved onto the land -




12.  What is a ligand?



13.   What are two features that needed to be present in the very first “living” systems?


14.  What are two features that would probably have shown up very late before early living systems became recognizable as “true” living systems?


15.  What are two different ways that minerals can be used in our bodies?  Don’t be too vague.



16.  What exactly is a hydrothermal vent?







Answer any four of the following questions for Eight Points Each.

Note:  if you answer more than four, only the first four will be corrected.

            You can get partial credit on these answers.


1.  What are four different ways that anaerobic organisms impact humans? 




2.   For the main photosynthesis reactions:

Exact Materials or Energy Used

Exact Materials Produced




3.   For each step in the theoretical development of Life on Earth, put them in chronological order, from earliest to latest, 1 - 8 in the boxes to the left.
















onto Land




4.       Briefly describe the three different ways that enzyme inhibition can work.






5.   Answer the questions on the graph for the relationship between enzyme activity and temperature.   A.  Why is the rate dropping off here?  B.  What is this point called?  C.  Why is the rate rising here?




                                                                  *                *
                                                              *                        *
Reaction                                      C    *                             *   A
Rate                                                 *                                   * 
                                                       *                                       *
                                                  *                                                    *
                                         *                                                                       *
                          *****                                                                                         ******


6.   For oxygen debt -

Tissue it

happens in -

Conditions it

happens during

What is



7.   What are four of the challenges of moving to land from aquatic systems?






Link to Answer Key




Answer as many as you are able.  Wrong answers will not result in points being lost from the main exam.   You can get partial credit on these answers.


When people say that Life violates the 2nd Law of Thermodynamics, what do they mean?  Three Points.



Why does Life actually NOT violate that Law?  Three Points.



Explain why traits produced by metabolic pathways would pretty much have to be multiple-gene traits.  Three Points.



In the rate reaction graphs, one of them had two curves.  Why?  Three Points.



When a protein denatures, what’s happening inside the molecule?  Three Points.



Where exactly do nitrogenous wastes come from?  Three Points.



What evidence might support panspermia?  Three Points Each.



With continental drift, sedimentary rocks might have formed and moved long distances to where they are now.  What feature of the rocks can be used to determine the original latitude of the sediments when they formed?  Three Points.



What do plants generally need done by fungi or bacteria?  Three Points.




Why do some people think that Nemesis exists?  Three Points.







SCI 135 

Michael McDarby


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