BIO 170  - Second Exam  - 2019
Answer Key



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.  Applying sterilization techniques to surgery was first done by

                        a.  Pasteur                  b.  Cohn                        c.  Lister

                        d.  Koch                          e.  Past Doctor Surgeon-Guy

                        ...who was actually d, and who sprayed carbolic acid acoss his

                                 operating room.



___B___ 2.  A near-extinction event can produce a

                        a.   Mutational threshold                     b.  Bottleneck effect

                        c.   Sporation effect                            d.  Weinberg threshold

                                                            e.  Lot of anxiety

               basically "pinches" the gene pool to a new set of

                                starting ratios.



___D___ 3.  Reradiation generally causes changes in

                        a.  Frequency                  b.  Wavelength                     c.  Energy levels

                        d.  All of these                e.   People’s happiness with “used” on ebay

                        ...they are all connected to each other.



___C___ 4.  In the modern synthesis, evolution produces changes in

                        a.  Mutations               b.  Average individuals           c.  Allele ratios           

                        d.  Populations                        e.  Hairstyles

               changes the gene pool generation by generation.



___C___5.  Production of single-species microbe cultures was a technique developed by

                        a.  Cohn                       b.  Pasteur                   c.  Lister

                        d.  Koch                                  e.  My great-grandma

                        ...yeah, the Past Doctor Surgeon Guy developed the serial dilution-of-tiny

                              samples to purify cultures to single species.



___D___6.  Which supplies plants stems with structural support?

                        a.  Rhizoids                 b.  Mucopolysaccharides                     c.  Protein struts

                        d.  Central vacuoles                 e.  What about emotional support?


                         ...these fluid-pressurized chambers stiffen the stems.




___A___7.  Plants mostly use human-digestible starches for

                        a.  Storage                   b.  Respiration             c.  Structure

                        d.  Photosynthesis                   e.  Cheating on diets


                         ...the reason they are more easily broken down is that the plants "plan"

                               to break them down later to use for their own needs.


___D___8.  Alternation of generations is a common process in

                        a.  Prokaryotes             b.  Fungi                      c.  Eukaryotes

                        d.  Parasites                             e.  Generations that…altern?


                         ...often in different hosts, apparently to take advantage of each mode's upside.


___B___9.  Almost all land plants use symbionts for

                        a.  Aerobic respiration                        b.  Nitrogen fixation

                        c.  Immune defense                            d.  Photosynthesis

                                                e.  Evading taxes


                         ...without a source of nitrates, the plants can't build amino acids / proteins.


___A___10.    Bacterial cultures are commonly grown with what nutrient-infused material?

                        a.  Gelatin                                            b.   Starch sheeting

                        c.  Saline solution                               d.   Special plastic

                                    e.  Whatever’s lining my nasal passage


                         ...usually a gelation called agar.


___D___11.   Sugars from photosynthesis would be transported in

                        a.  Rhizoids                 b.  Xylem                    c.  Sporophytes

                        d.  Phloem                               e.  Cute little packets


                         ...that's the downward-moving tubes in vascular plants.


___A___12.   DNA forensics became a widely-useful technique with the development of

                        a.  Polymerase Chain Reaction                       b.  Human Genome Project

                        c.  Epigenetics applications                             d.  Molecular clocks

                                                e.  The CSI television empire


               amplifies tiny DNA samples to levels that can be analyzed.




___B___13.   Which is in opposition to root pressure?

                        a.  Osmosis                  b.  Gravity                   c.  Cell walls

                        d.  Transpiration          e.  What are the roots being pressured to do?


                        ...osmotic pressure can drive water up until the downward pull

                              of its own weight is too strong.


___C___14.  Early sterilization techniques could be unreliable because they often

                        a.  Produced dangerous toxins                        b.  Mutated the targets

                        c.  Did not affect spores                              d.  All of these

                                                e.  Produced musical side effects

               there will still potential live cells after sterilization.



___D___15.   Most marine algae have a color that can be connected to

                        a.  Water mineral content                               b.  Fresh water content

                        c.  Season                                                     d.  Depth

                                                            e.  Overall prettiness

                        ...they differ is the pigments that are best functional with the

                                 frequencies that get down to them.



___B___16.   Plants often use minerals

                        a.  For capturing of light frequencies

                        b.  Incorporated into protein molecules

                        c.  For resisting osmotic pressure

                        d.  For additional structure

                        e.  For stable investment portfolios

                        ...a common use of minerals in animals as well.

                            (c could be true, even a, but beyond the scope of this course)



___B___17.   Which is most likely to be picked up in a medical facility?

                        a.   Viral infection                     b.  Gram-positive infection

                        c.   Protozoan                          d.  Gram-negative infection

                                                e.   A cute intern?

                        ...they often resist the effects of antibiotics and antiseptics,

                                 and so survive better there.



___C___18.   Which feature can be diagnostic for tracheophytes?

                        a.  Pollen                     b.  True roots                           c.  Sori

                        d.  Lignin                     e.  Do they get sick?

                        ...they are the spore-producing packets on the leaf undersides.


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.  According to the endosymbiont theory, what eukaryote abilities are connected to ancient prokaryotes that were ingested?

 Aerobic Respiration
(the mitochondrion)



(the chloroplast)

2.  What’s it mean if a species is monoecious?

                         ...individuals are male and female simultaneously.


3.  When bacteria are “tweaked” to take in and use human genes, how is it determined that they have actually picked up the genes and expressed them?


                         ...the plasmids also contain marker genes, which give the recipients a noticeable ability.  Often antibiotic resistance - treat with antibiotics, and only those that have picked up and are using the plasmid genes survive.


4.  What are holdfasts?

         Structure that hold algae to rocks

In what ecosystem would holdfasts be common?      Surf zones 


5.  The laboratory technique called sectioning -

WHAT      Thin-slicing

     IS          specimens


 WHY            Allows transmission

 IS IT               microscope beam

NEEDED?     to go through

6.  Why do plants need their stomates to be -

OPEN?   Let carbon dioxide in 


CLOSED?  Restrict water loss

7.  What “adjustment language” was added later to the cell theory?

                         ...cells only come from other RELATED cells. 


8.  Many antibiotics originated in fungi.  Why are they making them?


                         ...they compete with bacteria for food, so they kill them.



9.   The evolution of the diseases carried by explorers depended on what two features of European civilization?

 Large cities 


Many cities in a closely-linked network. 

10. How do epigenetic modifications in bacteria follow Lamarckian inheritance patterns?


               makes it appear that needed adaptations just appear as they are needed, like it was planned out ahead of time. 


11.  For two different bacterial shape-based groups, give the term and then describe or draw the basic shape.

 Coccus - round

Vibrio - short curve


Spirochetes - Curly 



Bacillus - bar-shaped

Spirillum - wavy

12.  Two totally different uses plants have for carotenoids -

 Capture "extra" light frequencies 


Give "signal" colors

to flowers, fruits, etc 


13.  Why does the resolution of light microscopes “top out” at around 1200X?


                         ...the tiniest visible gaps are now the same width as the light waves trying to sneak through - smaller gaps just block them.


14.  In what way can transpiration be reasonably called -

A BAD         Loses water that the

THING?        plant needs 


A GOOD    Helps draw water up.

THING?   Critical part of ecosystem

                        water cycle.

15.  What is the major weakness of the hypothesis linking volume-surface ratios to apparent cell size limits?


                         ...the math is for spherical cells - it doesn't apply to most cells that have much more surface available.


16.  What two water properties help it move up plant vascular systems?

 Cohesion - water sticks to itself,

helps pull the column up. 


 Adhesion - water sticks to the edges of the xylem, resists dropping.




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 challenges any invasive microbe faces using the human body as an ecosystem.

 Needs to be able to access

the resources it particularly


 Needs to evade host defenses,

at least for a while. 


 Needs to be able to move offspring

to new host.


2.  Give three sets of differences that exist between the groups -



 Virtually no separate internal chambers


Many separate internal chambers 

 Single chromosomes


 Pairs of gene-matched chromosomes

 Loop-shaped chromosomes


2-ended chrmosomes 

Significantly smaller
Significantly larger
Not found in multi-celled systems
Capable of multicellularity


3.  Other than the genders involved, give four sets of differences between -



 Much smaller


Much larger

(holds food for offspring) 

 Made in much larger quantities


Made in comparatively

fewer quantities 

 Have a way of getting to

where the egg cells are 

 Must be reached

by the sperm

 In production, 1 starting cell

produces 4 working sperm 

In production, 1 starting cell

produces 1 working egg cell

and 3 polar bodies 


4.  What are four basic requirements, in Hardy-Weinberg Equilibrium, that either an allele or the gene pool requires?


 No natural selection


No sexual selection 

No migration, in or out

No mutation


Very large population






5.  What are the Koch Postulates for possible disease organisms?


 They are found in

all diseased individuals


They can be culture from

diseased individuals 

The ones from the cultures

can cause the disease 



Ones from those individuals

match the original culture


6.  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 


                *         * /  *       *                           *  \  *  
         X-Ray          UV    Violet    Blue                           Red    InfraRed




7.  Microscopes can be split into two main groups based upon either listed feature.  For each feature, name the groups.

Nature of the

Imaging Beam





Interaction of Beam

with specimen






8.  Describe (don’t just give a term) for four different types of reproductive isolation that can occur in evolving populations.


 Separation by environmental boundaries


Subgroups in different niches 

Subgroups reproducing at different times 


Subgroups us different reproductive behaviors

Subgroups nor physically compatible for copulation

Subgroups not chemically / immunologically compatible for reproduction




BONUS QUESTIONS.  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.


Other than the final product, what were the main immediate developments of the Human Genome Project?  Three Points.



What issue needed to be solved to develop high-resolution magnifying lenses?  Three Points.



What did Malpighi realize from his study of goldfish?  Three Points.    



What products did Pasteur first work with?  Three Points.



What causes Brownian motion?  Three Points.   



After a disease has gotten milder, there are often slight increases in virulence in variants.  Why?  Three Points.



What disease might have come back to Europe from the explorers?  Three Points.



What is a nosocomial infection?  Three Points.



Why would a new antibiotic not be a particularly profitable drug?  Three Points.




Why would a small population evolve much faster than a large one?  Three Points.





How can a brightly-colored fish actually be very well camouflaged?  Three Points.




BIO 170

Michael McDarby