BI 171 - Second Exam - 2009

Links connect to relevant parts of the online book.

Multiple Choice.

Place the letter of the choice that best answers the question on the line to the left.
Two Points Each. NOTE: "e" answers are never the correct answer.

_______ 1.  Liver cells absorb sugar and make starch with them through

                    a. Dehydration synthesis             b. Aerobic respiration            c. Photosynthesis             d. Hydrolysis
                                                            e. Some complicated chemistry thingy


_______ 2.  Molecules are polar because of

                    a. Their basic shape             b. Distribution of ions            c. An external magnetic field             d. Unequal sharing of electrons
                                                                                e. Being really, really far north...or south...

_______ 3.  In comparison to a solution with a pH of 9, one that has a pH of 11 would be

                    a. 4 times as acidic             b. 4 times as basic            c. 100 times as acidic             d. 100 times as basic            e. Two years older


_______ 4.  Carbon dating tends to not work for samples older than 60,000 years because

                    a. The half-life is 60,000 years            b. There was very little radioactive carbon to start            c. Radioactive nitrogen confuses the readings
                    d. Too much is radioactive if it's older                            e. The other carbons all want someone younger

_______ 5.  Which must be a polymer?

                    a. Sucrose             b. Sucrase             c. Sucranol             d. Sucraic acid            e. Doesn't it have a choice? Isn't this America?


_______ 6.  Memetic types of epigenetic factors may follow LaMarckian patterns because they are

                    a. Embedded in shared information                     b. Dependent upon isolation                    c. Acquired then passed on
                    d. Protein-based                                        e. That's one, two, three separate bits that make no sense to me

_______ 7.  The presence of double bonds means an organic molecule

                    a. Is easily ionized             b. Will form a ring structure            c. Is unsaturated             d. Will also have hydrogen bonds
                                                                                e. Is really willing to commit

_______ 8.  A plasmid allows

                    a. Genetic sharing among prokaryotes            b. Movement through a lipid barrier            c. Protein subunits to stay together in a functional unit
                    d. Information to be shared epigenetically                                e. A really weird word a place to live

_______ 9.  The different amino acids have different

                    a. Chiral twists             b. Amino groups             c. R groups            d. pH's             e. Daddies


_______ 10.  There are three fatty acids in a lipid molecule because

                    a. There are three "corners" on the central ring                                        b. Glycerol has three carbons
                    c. They can only cross-connect at three points                                         d. All of the above
                                                        e. Any more and there's always a fistfight

_______ 11. An ethanol (derived from ethane) molecule would have how many carbon atoms?

                    a. Six             b. Four             c. Two             d. One            e. Keeping score will hurt their self-esteem

_______ 12. A hydration shell happens

                    a. Under surface tension             b. Around solute particles            c. On the early, cooling Earth             d. Within lipid droplets
                                                                                e. When you give your turtle Gatorade

_______ 13. Chaperonins are involved in regulating

                    a. Protein conformation                 b. Starch isomers                c. DNA transcription                 d. DNA translation
                                                e. Proper dance distance (although bribes are accepted during tangos)

_______ 14.  Stereospecificity is a feature of

                    a. Complex starches             b. Protein domains             c. Lipid layers            d. DNA strands             e. Earbuds

_______ 15. Water is most dense at

                    a. 0o C             b. 1o C             c. -100o C             d. 4o C             e. Exam time

_______ 16. The "active" energy in a cow's ATP is usually

                    a. Holding enzymes together                        b. Transferred into acids                        c. One step from being light energy
                    d. Two steps from being light energy                                        e. Um, a cow???

_______ 17. Free radicals are very reactive because their

                    a. Nuclei are unstable                         b. Outer electron shell is too full                        c. Protons repel their electrons
                    d. Outer electron shell isn't full                                        e. Fellow radicals are still imprisoned

_______ 18.  What is carried by transfer RNA?

                    a. Genes             b. Chromosomes             c. Amino acids            d. Enzymes             e. College transcripts

Short Answer.

Pick NINE questions to answer in the spaces provided.
NOTE: if you answer MORE than nine, only the first nine will be corrected.
Four Points each. Partial credit is possible.

1.   How might the "snowball period" have led directly to the Cambrian Explosion?


2.  Ignore the specifics - label with the general terms applied to any chemical reaction -

CO2         +        H2O              light >           C6H12O6      +            O2

---------------     ---------------     -----------------     ----------------     -----------------

3.  What are two different biological uses for lipids?


4.  Based on general
chemical function, what
sort of chemical are enzymes?
4b. How do enzymes
perform that
5.  What are two Hardy-Weinberg conditions that do not involve a type of selection?


6.  Briefly describe two different ways that populations in the same ecosystem can become niche isolated.


7.  What are two features the first "living" molecular systems had to have?


8.  What are two features that would not have been there early, but which had to appear in "living systems" for them to be Life as we know it?


9.  Briefly explain how a bottleneck affects a gene pool.


10. Give the messenger RNA strand that would be made from this part of a DNA strand:

C   T   A   G   G   A   T   T   A   G   C   T   C   C   T   A   A   C


2-Point Bonus: How many codons are there here? ___________________

11. Briefly explain why evaporation is a cooling process.


12. For each system, give a type of protein that must be present for the system's basic function:



13. What two elements, other than C, H, N, and O, are extremely common in biological molecules?


14. What are two different general circumstances that support alternation of generations in groups of organisms?


15. What biological factor (other than actual extinctions) has probably happened in every mass extinction event?


16. What are the functions of the two "ends" of an antibody molecule?



Long Answer.

Select and answer completely any four of the following questions.
Note: if you answer more than four, only the first four will be corrected.
Seven Points Each. Partial credit is possible.

1.  For carbohydrates:
Basic formula of
simple carbohydrate: ___________________________
Basic uses of starches
in plants:


Name of basic process
that creates glucose:


2.  Name and describe the three basic bond types.






3.  Using the numbers of bonds as a guide, fill in the symbols for either Carbon, Hydrogen, Nitrogen, or Oxygen.

This would be a drawn picture of boxes connected by bond lines.


Three-Point Bonus - What specific type of molecule is this? ___________________
4.  For sexual reproduction - Basic


Advantage over


compared to asexual


5.  What are four different steps, in order, of the origins of Life on Earth that would have happened before recognizable eukaryote cells were present?













Column 2

How many
How many
How many
electrons?(Radical form)
ion form?
7.  Name and give a description of the four levels of protein structure.








8.   For four functional organic molecule groups, give the name, then show the arrangement of atoms in enough detail to demonstrate completely how each group works.









Link to Answer Key


Answer as many or as few as you wish. You can't lose points on the rest of the exam by getting these wrong. Partial credit is possible.

How can getting an antibiotic for a virus infection lead to the much later development of an antibiotic-resistant bacterial infection? Three Points.

What source of DNA other than mitochondrial DNA is preferred for evolutionary studies (Two Points), and why? (Three Points)

How would a plant produce a gamete-based isolation? Three Points.

How primordial soup might have settled out on a planetary body is being studied in a real-world situation right now. How? Three Points.

Why does the periodic table have wider and wider "bridges" on the lower rows? Three Points.

What atom, other than the "big four," commonly forms covalent "bridges" in protein molecules? Three Points.

Why is a "universal flu vaccine," using a part of the surface molecules that is always the same, probably not going to work? Three Points

What is added to table sugar to make Splenda? Two Points.

And why does that make it largely undigestible? Three Points.




BI 171

Michael McDarby


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