BIO 171  - Third Exam  - 2014

Answer Key

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.


___C___ 1.    What makes rough endoplasmic reticulum “rough”?

                        a.  DNA                          b.  Cell walls                       c.  Ribosomes

                        d.  Microfilaments            e.  It grew up in a bad neighborhood

                        ...they're embedded in the ER membranes.




___D___  2.  C. elegans has been an important source of information about

                        a.  Plant processes                   b.  Genetic basics

                        c.  Human health                     d.  Developmental processes

                                                e.  How to dress nice

               adults, they have the same cell number, and tracking how each

                           develops from the first cell was the early research.




___C____ 3.    Apoptosis would result in a cell being

                        a.  Mobile with pseudopods                            b.  Differentiated

                        c.  Dead                                                        d.  Prepped for division            

                                                e.  A new Daddy?

            's death initiated within the cell itself, programmed in.




___A___ 4.    A cell plate first appears as

                        a.  Golgi vesicles                                 b.  Microtubules

                        c.  Microfilaments                                 d.  Endoplasmic reticulum

                                    e.   More inexpensive dinnerware

                      ...the forming cell plate is technically a secretion.



___D___ 5.    Telomerase would be least active in cells under which condition?

                        a.  Sex cell formation                              b.  Embryonic development

                        c.  Cancer growth                                   d.  Old age

                        e.  Is that what they sing in the background of “The Lion Sleeps Tonight”?

                      ...that's when many cells stop making it, contibuting to aging processes.




___B___ 6.   During which stage(s) of the cell cycle would cytokinesis definitely not happen?

                        a.  Interphase only                               b.  Prophase and metaphase

                        c.  Metaphase and anaphase                 d.  Anaphase and telophase

                        e.  Well, you can’t do it when someone is looking…

                      ...the cell has to ready to divide, and it isn't then.


___C___ 7.    Malignant cancer cells have activated genes that make

                        a.   Golgi bodies                      b.  Spindle fibers                     c.  Pseudopods

                        d.   Mitochondria                    e.  Very bad decisions for you

                      ...which allow some cells to crawl away from the original tumor.




___C___ 8.    Microvilli would aid a cell involved in

                        a.  Mobility                                      b.  Reproduction

                        c.  Absorption                                  d.  Disease resistance

                                    e.  Shady business dealings

             increasing its surface / exchange area.




___D___ 9.    Sperm are able to find an egg cell through

                        a.  2nd messenger molecules                     b.  Negative chemotaxis

                        c.  Osmotic pressure differences               d.  Positive chemotaxis

                                                e.  Ads on Craigslist

             detects molecules released by the egg cell and travel toward it.




___B___ 10.    Sectioning refers to

                        a.  Organelle subdivisions                               b.  Specimen preparation

                        c.  How mitotic stages change                        d.  Embryonic development

                                                            e.  Buying concert tickets

             makes specimens thin enough that a transmission microscope beam

                          can go through them.




___C___ 11.   Nervous systems develop from

                        a.  Mesoderm                          b.  Endoderm                          c.  Ectoderm

                        d.  Dendroderm                      e.  Dermaderm…aderm…aderm…

                      ...the systems derive from surface features that sink beneath the surface.




___A___ 12.   Storage and processing of RNA is done specifically in the

                        a.  Nucleolus                                       b.  Golgi bodies

                        c.  Nuclear envelope                            d.  MTOC

                                    e.  Back of a “service station” on 58th street

            's what it does.


___C___ 13.  When a freshwater plant moves phosphate from the low-concentration area
                                    of the pond into the higher-concentration area of the cytoplasm, that is

                        a.  Synthesis                           b.  Exocytosis              c.  Active transport

                        d. Passive transport                 e.  Probably going to get someone in trouble

                      ...the low-to-high ("uphill") movement is the clue.




___A___ 14.   A mutation that made eyes grow all over fruit flies proved to be a mutation in

                        a.  A HOX gene                                  b.  A microtubule pathway

                        c.  A G protein gene                            d.  A microfilament pathway

                                    e.  The new fils It’s Always Looking at You!!!

             eye-placement (basic layout) gene that turned out to be

                           homologous to a gene in mice.




___D___ 15.   Directed motion of materials in a cell can be done with

                        a.  Ribosomes and microfilaments

                        b.  Mitochondria and microtubules

                        c.  Vesicles and ribosomes

                        d.  Microtubules and endoplasmic reticulum

                        e.  Wires and teeny drones

                      ...directed = from here to there, either in ER canals or on microtubule conveyors.




___B___ 16.   Some plants hit a size limit based on the relationship between

                        a.  Turgor pressure and root pressure

                        b.  Root pressure and gravity

                        c.  Size and volume

                        d.  Flux and counterflux

                        e.  How they look and how they think they look

                      ...the force of osmotic movement in against the weight of the water.




___C___ 17.   Okazaki fragments are a feature of

                        a.  Spindle breakdown                                                b.  Unequal crossing over

                        c.  DNA replication                                         d.  Transduction message splits

                                                e.  Very fast sushi preparation

            's the bit-by-bit replication on the "other" side.




___A___ 18.   Which makes sense for an individual in a monoecious species?

                        a.  Both male and female parts

                        b.  Only able to do either asexual or sexual reproduction

                        c.  Only able to do asexual reproduction

                        d.  Shows no particular gender

                        e.  No one wants to Friend them

                      ...individuals are both male and female at the same time.


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.   For dynein and kinesin -

How are

they the      They attach molecules to microtubules in cells


How are

   they          Once attached, they move in opposite directions


2.   What two major but totally different functions occur during interphase?
Cells do whatever their basic functions are
Cells prepare for divisions
3.    What are two different enzymes involved in DNA replication?

DNA Polymerase
4.    Viruses violate some of the rules of the Cell Theory.  What are two such violations?
Not cellular.

No metabolism in "free" form.
No growth or development stages.

Virtually no enviornmental interaction in "free" form.
5.    Briefly explain,  for the fluid mosaic model of cell membranes -


   it’s          The phospholipids move freely in the layers.

fluid -


it’s a        The embedded proteins form functional patterns.

mosaic -

6.   What is the 9+2 arrangement?


 's how microtubules are arranged in cilia and flagella. 

7.   Briefly explain how an individual winds up with extra copies of a few genes.


            ...crossing over exchanges unequal pieces of chromosomes, and the longer ones get passed on with extra copies of the genes. 

8.   What are two strong pieces of evidence that support the endosymbiosis theory?
Organelles match existing prokaryotes in structure.

Organelles match existing prokaryotes in chemistry.
Organelles have prokaryote-type chromosomes.

Modern eukaryotes sometimes take in and use prokaryotes.

9.    What typically happens in a positive feedback loop?


             ...message gets fed through repeatedly, amplified each time. 

10.  What are two different ways that organisms can prevent damage from exposure to the hypotonic conditions of fresh water ecosystems?
Incoming water pumped back out.

Cells casings prevent overfilling of cells.
Most surfaces waterproofed.

11.  What are two different ways by which polyspermy is prevented?
Only one sperm nucleus allowed in.

Only one sperm nucleus allowed into fusion.

Extra sperm nuclei expelled.

Extra sperm nuclei broken down.
12.  The most commonly-presented explanation for why cells seem to have maximum size limits deals with the mathematical relationship between what two aspects of a cell?
(If spherical cell doubles...)
Surface area
( surface does not double)

13.  What is the “pull strength” rule for spindle fibers?


             ...the longer the spindle fiber, the stronger the pull (sets up tug-of-war that puts chromosomes at equator). 

14.  How is the developmental potential different between cells made by -


CLEAVAGE?     Eventual cell fates are set very early. 


CLEAVAGE?     Fates stay flexible for a long time. 

15.   Give two different broad classes of signal ligands.



16.  What and where is glycocalex?


   's a protein-carbohydrate material on cell surfaces. often involved in cell-cell interactions. 

17.  What are two different Kingdoms that have cell walls as a definitive feature?
Plants/ Plantae



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 the two basic types of cells, give the type and two sets of differences between them -
Prokaryote Eukaryote
No internal of, separate membranes / no nucleus. Have internal, separate membrane chambers / have nucleus.
Have single chromosome. Have pairs of homologous chromosomes.
Chromosomes are loops. Chromosomes are 2-ended.
Not found in multi-celled systems. May act in multicelled systems.
Produce plasmids. Don't make plasmids.
2.    Fill in the steps of transduction between the listed steps.
Receptor picks up ligand.    ---->
Message passes by way of other molecules through membrane.
2   G proteins activated inside cell / on inner membrane surface.
Second messenger activated
4   Kinase activated, interacts with necessary enzyme. Proper enzyme starts to work. 

3.   Give the functions (names are NOT enough) of three different membrane protein types.
Used for identification in muleicelled systems (Markers)
Used to pick up information from environment (Receptors)
Used to allow small uncharged particles through (Pores / Channels).
Used to allow materials through, but can be opened & closed (Gates). Used to move materials against concentration gradient (Pumps).
Used to connect / interact with other cells (Connectors). Help move things through that can't pass through membrane or pores (Carriers).
4.   For two different types of vesicles or vacuoles -
Structure NAME Structure FUNCTION
Contractile Vacuole Pumps out water entering by osmosis.
Central Vacuole. Provides stiffness to small green plants.
Food Vacuole. Takes in larger particles for breakdown & absorption.
Lysosome. Digestive enzymes, involved with food vacuoles and apoptosis.
Peroxisome. Involved in recycling of cell materials.
Golgi vesicles. Carry secretions up to surface.
Storage vesicles. Hold onto materials.

5.   Give three sets of differences (other than the associated genders) between -
Much smaller. Larger (Holds food for offspring).
Many more made. Fewer made.
Has way of getting to where egg cells are. Must be reached by sperm.
One starting cell used to make 4 functional sperm. One starting cell makes one functional egg cell and 3 polar bodies.
6.   Briefly describe four ways that flux can be increased through a barrier.
Decrease particle size. Increase temperature.
Increase exchange surface area. Make concentration gradient steeper.

7.   For each category of microscope, there are two different terms that apply.
of the
Imaging Beam

How the Beam

Interacts with



8.   Give the name and function of three different types of plant tissues.
Meristem New cell production
Ground Tissue Photosynthesis and support
Vascular Tissue Move materials up and down
Dermal Tissue Coverings





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 is resolution measured?  (Not looking for units here) Three Points.



Where are giant amebas found?  Three Points.



How are plasmids associated with doctors not giving antibiotics to folks with viral infections?  Three Points.



Why do evolutionary researchers prefer to use mitochondrial DNA rather than nuclear DNA?  Three Points.



To what materials is the Earth a permeable barrier?  Three Points.



As diffusion moves toward equilibrium, the progress gets slower and slower.  Why?  Three Points.




What well-known cell structure apparently has no accepted name?  Three Points




What is probably true of organisms that have no response to destructive polyspermy?  Three Points.





What is the “dirty little secret” of stem cell research?  Three Points.








BI 171



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