BI 171 - Third Exam - 2008

Each question's number is linked to the relevant part of the online book, if possible (some questions relate to multiple sections).

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.  What part of a cell membrane is most likely to move around fluidly?

                    a. Proteins         b. Histones         c. Phospholipids        d. Minerals         e. The flowy bits

_______ 2.  A shift in pH usually affects enzymes through an effect on

                    a. Temperature         b. Inhibitor binding        c. Use of oxygen         d. Hydrogen bonds        e. Their self-esteem

_______ 3.  Okazaki fragments are made of

                    a. RNA             b. Tubulin             c. DNA             d. Pore proteins             e. Bits of okazaki

_______ 4.  The endosymbiont theory applies to the

                    a. Mitochondrion and chloroplast                 b. Mitochondrion and cell wall                c. Nucleus and cell wall
                    d. Flagellum and cilia                            e. List of things with unnecessarily complicated names

_______ 5.  If a reaction uses multiple reactants, the reactant in shortest supply should be the

                    a. Michaelis minimum             b. Inhibitor            c. Regulatory substrate             d. Limiting factor
                                                                        e. One on your shopping list

_______ 6.  Chromatids become chromosomes when

                    a. They separate at the centromeres                    b. They connect to spindle fibers
                    c. They wrap around histones                             d. They are used to make proteins
                                                    e. They submit the proper paperwork

_______ 7.  Cytokinesis should never happen during

                    a. Interphase             b. Anaphase             c. Prophase            d. Telophase             e. November

_______ 8.  Which molecular complex would be storing RNA?

a. Nucleolus             b. Chromosome             c. Golgi complex            d. Centrosome             e. Why, is it worth something?

_______ 9.  In a Q
10, the "Q" part is

                    a. Equilibrium             b. Reaction rate             c. Flux rate            d. Affinity             e. Can't I do the "10" part?

_______ 10.  Lysosomes are associated with

                    a. Secretion             b. Division             c. Movement            d. Digestion             e. Not telling the truth

_______ 11.  Helicase is a key enzyme in

                    a. Absorption             b. DNA replication             c. Spindle formation            d. Membrane formation             e. Doing a heli a job

_______ 12. A metal ion that must bind temporarily to an enzyme's active site for the site to work:

                    a. Prosthetic group             b. Coenzyme            c. Cofactor             d. Inhibitor            e. Metal buddy

_______ 13.  An allosteric effect involves

                    a. Ionization             b. Gene expression             c. Enclosure            d. Shape changes             e. An effect that's steric, in an allo way

_______ 14.  Where is there likely to be a MTOC?

                    a. Mitochondrion             b. Nucleus             c. Rough endoplasmic reticulum             d. Base of flagellum            e. Um, IDY

_______ 15.  What is the primary content of a polar body?

a. Spindle             b. Secretion             c. Carbohydrates            d. Chromosomes             e. Blubber

_______ 16.  In many coupled reactions,

a. ATP provides the exergonic reaction                        b. ATP provides the endergonic reaction
                    c. Only the exergonic reaction uses enzymes                d. Only the endergonic reaction uses enzymes
                                                        e. Things are okay until one reaction cheats

_______ 17.  Actin is a

                    a. Phospholipid found in cilia                 b. Protein in membrane pumps                c. Nucleic acid in centromeres
                    d. Protein in microfilaments                                e. Something you might combine with singin and dancin

_______ 18.  What disappears during prophase?

a. Chromosomes             b. Nucleolus             c. Spindle            d. Cell wall             e. Dignity


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.  Name two different types of functional vacuoles.


2.  Give two sets of differences between -







3.  Intermediate filaments can often be found in cells under what special conditions?


4.  Explain why the reaction rate drops off on both sides of the optimum temperature -
5.  What are two different materials to which a typical cell membrane is permeable?


6.  For dynein and kinesin -
7.  What is the key feature by which active transport can be recognized?


8.  How exactly does a phospholipid molecule from a cell membrane differ from a "typical" lipid molecule?


9.  In point mutations, why is an deletion usually much worse than a substitution?


10.  Describe two different ways that indirect enzyme inhibition can work.


11.  What are two different ways to prevent on ongoing chemical reaction from reaching dynamic equilibrium?


12.  What is the main purpose of microvilli?


13.  What two things happen during group translocation?


14.  Briefly describe two things that happen when prokaryotes divide that do not happen when eukaryotes divide.



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.  Give three different ways of adapting to hypotonic conditions, and for each give an example of an organism that uses that adaptation.







2.  In the graph below of Michaelis-Menten Kinetics, explain why the curve is doing what it's doing at each marked point, in terms of the enzyme molecules at work.    The graph itself isn't completely shown here, but it's in the notes and linked to in the book.


                                                                                                 Label on top flat part of graph

Reaction                                                 Label where curve begins to flatten out


  V                                                  Label on rising part of graph.

                                                      Substrate Concentration (as Enzymes remain constant) ---->

3.  Describe the functions of three different types of membrane proteins.






4. Fill in the arrow-headed labels on this drawing of eukaryote cell structures.
As it says, this was a hand-drawing of a cell with various structures pointed at.


5.  What are three sets of differences between mitosis and meiosis?






6.  Briefly describe four ways that flux can be increased through a barrier.




7.  Give three sets of differences (other than the associated genders) between -










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.

Many reactions that happen in cells are not reversible in any practical way. Why not? Three Points.

In a graph of enzyme-catalyzed reaction rate and temperature, what sort of organisms typically have very broad but fairly short curves? Three Points.

What sorts of materials often show an ability to irreversibly inhibit enzymes? Three Points.

What detoxification pathway shares an enzyme with acetaminophen? Three Points.

What's the major difference between the two pronunciations of apoptosis? Three Points.

Why is mitochondrial DNA preferable for use in molecular clocks? Three Points.

What sort of animal is covered with microvilli? Three Points.

What would the ligand for a hormone receptor be? Three Points.


How can crossing over be used to map gene locations on chromosomes? Four Points.



BI 171



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