SCI 135 - Fourth Exam Spring 2014




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.  In respiration and photosynthesis, water plays an important role in

_______                a.  Absorbing and changing energy

b.  Reducing activation energy

c.  Controlling enzyme activity

d.  Moving electrons around

e.  Keeping everything wet



                     2.  The “plant problem” relates to

_______                 a.  Low light levels                           b.  Life’s beginnings

                              c.  Mass extinctions                        d.  Moving to land

                                    e.  Buying certain kinds without getting arrested



                      3.  The beginnings of photosynthesis can be seen in the fossil record

                                                in thick layers of

_______                 a.  Plants                    b.  Advanced animals                      c.  Rust

                             d.  Coal                       e.  Announcement posters



4.  Dietary minerals often are used in the body as

_______                a.  Enzymes                            b.  Coenzymes                      c.  Vitamins

d.  Cofactors                          e.  The rocks in our heads



                     5.  The appearance of sexual reproduction was directly connected to

                                                the evolution of

_______                 a.  Land plants                      b.  Paired chromosomes

                              c.  Land animals                   d.  Multicelled organisms

                                                            e.  The internet


                      6.  Glycolysis is

                              a.  Aerobic respiration                     b.  Anaerobic respiration

_______                  c.  Digestion                                     d.  Synthesis

                                    e.  Some made-up word to confuse us



                       7.  Ammonia results from

_______                 a.  Digestion of proteins                              b.  Digestion of lipids

  c.  Respiration of proteins                          d.  Respiration of lipids

  e.  Some big bald ambiguous guy putting it in a bottle



                        8.   The laws of thermodynamics explain

_______                   a.   How Life began

                                b.   Why so many reactions produce heat

                                c.   The basics of photosynthesis

                                d.   Primordial soup

                                e.   Where that weird ticket under your pillow came from


                        9.  Plants use fungal symbionts

_______                    a.  To mobilize nitrogen                  b.  To absorb water

                                 c.  To fight off pathogens                d.  To make ATP

                                                e.  For company


10.  The animals that survived the Cretaceous Extinction that killed most

                        the dinosaurs were most likely

__________              a.  Small scavengers                         b.  Small plant-eaters

    c.  Sea animals                                  d.  Single-celled

                                                            e.  Out of town at the time


                        11.  Chlorophyll

_______                   a.  Absorbs green frequencies                    b. Absorbs all frequencies

    c.  Reflects green frequencies                    d. Reflects all frequencies

e.  Is doing something nasty with frequencies


                        12.  Mass extinctions would be likely to produce a lot of

_______                    a.  Founder effects                           b.  Respiratory alterations

                                 c.  Point mutations                           d.  Bottleneck effects

                                                            e.  Orphan Facebook pages





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 forms of reproductive isolation that can occur to separate groups living in the same place and time?


2.  Two necessary features of “pre-Life” molecules.


3.  What are two different nutrients that plants need that are not input materials for photosynthesis?


4.  The two ways that ATP contributes energy to cell reactions:


5.  Aerobic respiration is considered much more efficient than anaerobic respiration.  On what basis is this comparison made - how is the efficiency decided?




6.  Photosynthesis probably arose as a combination of what two pre-existing systems?


7.  What is panspermia?




8.  Briefly explain where and under what circumstances oxygen debt occurs.




9.  What two features makes something a vitamin?

10.   The two likeliest staging areas from which aquatic organisms moved onto the land:

11.  What are two different uses plants have for carotenoids?

12.  In general, how do enzymes manage to speed up chemical reactions?




13.  ATP is used in a lot of coupled reactions.  What does that mean?




14.  In many ways, the processes of aerobic respiration and photosynthesis are mirror images of each other.  What are two ways, parts, or features of the processes that clearly do not match up?

15.  What were two major obstacles that faced water organisms as they moved to land?





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




2.  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.




Life on


















3.  For the main photosynthesis reactions:
Name Exact Materials or Energy Used Exact Materials Produced




4.  At the points labeled with the stars, attach the appropriate labels from this list: 

Violet.   X-Ray.  InfraRed.  Red.   Blue.   Ultraviolet.

            High Frequency       \                  Visible Range               /           Low Frequency

               *                       * /    *       *                               *       \   *



5.  According to the Hardy-Weinberg rules, what are four things that have to be true about a population for there to be NO change in allele frequencies over time?




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




7.  Below is a graph showing how enzyme activity, measured through the rate of the reaction catalyzed by the enzyme, reacts to changes in pH (NOT temperature!).  Fill in:  A)  The name given to the pH where the graph peaks; B) Why the graph peaks there;  C) and D) What's happening to the enzyme molecules as the rate drops off (C) below the peak; and (D) above the peak.



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

                                                                    pH ---->



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 cells turn into cancer, they spend less and less time in interphase.  Why?  Three Points.



According to E = mc2, what is Energy (conceptually, not mathematically)?  Three Points.



Although some folks claim it does, Life does not break the second law of thermodynamics.  Why not?  Three Points.



Which of our molecules have a low level of specificity?  Three Points.



What is likely to produce irreversible enzyme inhibition?  Three Points.



What human process has an optimal temperature below regular body temperature?  Three Points.



Where can primordial soup materials still be found?  Three Points Each.



Where is the “ozone hole”?  Three Points.



What is special about our local fossils?  Three Points.



Why do trees change color in the fall?  What happens?  Five Points.







SCI 135 

Michael McDarby


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