BI 173 - First Exam - 2003

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.

 

___B___ 1. One of the muscle subtypes is found only in

                        a. Arteries                     b. Insects                     c. Bats and birds
                        d. Vertebrates                         e. Arnold Schwarzenegger

                            ...it's fibrillar muscle, found in the insect flight systems and capable of
                                multiple contractions for each nerve impulse command.

 

___D___ 2. Which concept is most closely linked to Charles Lyell?

                             a. Population control                             b. Punctuated evolution
                       c. Artificial selection                              d. Gradual Evolution
   
                             e. The joke about making a small fortune in the wine business
   
                                                     (Punchline: Invest a large fortune)

                            ...the linkage is to Lyell's uniformitarianism, so it will be something long
                                and slow.

 

___A___ 3. Cladistics represents an approach to

                         a. Evolution                     b. Genetics                     c. Histology
                        d. Organic chemistry                     e. Terminal confusion

                            ...it also relates to classification, based on the appearance in a family
                                tree / evolutionary history of certain key features.

 

___D___ 4. Which type of microscope would most often require sectioned specimens?

                        a. Scanning                         b. Electron                     c. Light
   
                         d. Transmission                                 e. The microscopiest

                            ...the imaging beam goes through sections.

 

___A___5. Mitochondrial DNA is useful to evolutionary biology mostly because

                        a. It is only inherited along maternal lines
   
                          b. It does not recombine each generation
   
                          c. It has no active genes
   
                          d. It can be extracted better from fossils
   
                          e. It sounds more technical than the other choices

                            ...it does not mix-and-match each generation, but  is passed in the
                                egg cells.

 

___D___6. The adaptive value of an allele is determined by

                        a. Dominance                 b. Statistics                 c. Its frequency
   
                         d. Circumstances                         e. The Internal Revenue Service

                            ...an allele / trait variation is only as valuable as the current conditions
                                make it.

 

___C___7. Sexual selection has to exist in a balance between

                       a. Male and female
   
                         b. Available mates and available time
   
                         c. Survival success and reproductive success
   
                         d. Multiple genes and environmental interactions
   
                         e. What you want and what you can get

                            ...it's important to maximize your reproductive success, but not with a
                                trait too likely to get you killed before you can mate.

 

___B___8. In some flatworms, flame cells are part of excretion - where they exist, 
                                waste materials
are moved from the tissues to the more 
                                concentrated fluid of excretory tubes.  This process is

                             a. Diffusion                                    b. Active Transport
                       c. Osmosis                                     d. Passive Transport
   
                         e. Just one example of the disgusting stuff we have to learn

                            ...no, you haven't had flame cells yet, but that's not the issue -
                                what's important is that wastes are moving opposite to the
                                direction diffusion would move them passively.

 

___D___9. Niche isolation is a necessary step in the process of

                        a. Sexual selection                          b. The bottleneck effect
                        c. Natural selection                         d. Adaptive radiation
   
                                         e. Actually being able to scratch it

                            ...as members of a starting group divide into separate groups with
                                separate specialties, radiating into new niches.

 

___C___10. Real success, according to the Theory of Evolution by Natural Selection, 
                                    is most
closely tied to

                         a. Acquired characteristics             b. Survival                c. Reproduction 
                        d. Mutation   
                                                     e. Stock portfolios

                            ...it's important to survive, but pointless if you can't pass those traits
                                on.

 

___B___11. Which is true for dominant alleles?

                       a. Their effects are totally based on the DNA
   
                         b. Their effects are totally based on the proteins
   
                         c. They are more likely to be passed on
   
                         d. All of these are true
   
                         e. They hang out in leather bars

                            ...it's the coded-for proteins that "do the work."
                                (And don't jump blindly at "all of the above" answers!)

 

___B___12. Which should be hardest to properly control?

                         a. Observations                 b. Field studies                    c. Lab experiments
                        d. Hypotheses                    e. Drunken nerds in lab coats

                            ...you're basically trying to substitute observational organization for
                                controls, but it doesn't work too efficiently "out in the wild." 

 

___D___13. Darwin found that the similarities in species between mainland and islands 
                                were
related to

                        a. Climate only                                     b. Proximity only
                        c. History                                            d. Proximity and climate            
   
                         e. How seasick (or drunk) he was when he was drawing their pictures

                            ...Proximity = extent of isolation and uniqueness of starting communities,
                                climate = the natural part of natural selection.

 

___A___14. Neo-darwinism sees natural selection as bringing about

                       a. Shifts in allele frequencies               b. Increased extinctions
   
                         c. More and better adaptations                d. New and different species
   
                                         e. More stuff I haven’t quite learned yet

                            ...it's natural selection seen through a genetics perspective - evolution
                                alters the gene pool.

 

___C___15. The major evolutionary disadvantage to sexual reproduction is

                       a. Not enough variation                                    b. The need to always find a mate
   
                         c. Successful forms cannot be copied     d. All of the above
   
                                     e. This is tough - there’s just so little written about it...

                            ...every offspring is going to be different, which is good, but can't
                                exactly duplicate success.

 

___A___16. Which molecule type is most functionally dependent upon three-dimensional shape?

                        a. Protein                     b. Nucleic Acid                     c. Lipid
   
                         d. Carbohydrate                     e. The ones you have to look at with special glasses

                            ...the wide array of shapes allows a wide variety of uses.

 

___D___17. Which function is commonly associated with epithelial tissue?

                        a. Fat storage                                         b. Exerting a pulling force
   
                         c. Internal skeletal support                      d. Secretion
   
                             e. Does it come in a box or on a roll? ...Never mind...

                            ...it's the major non-lining / surface function of epithelium.

 

___B___18. A nucleolus should be full of

                        a. Sugars                     b. RNA                     c. DNA
   
                         d. Membranes                     e. Something nasty

                            ...it's the RNA storehouse / processing center

 

SHORT ANSWER. 

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

1. Briefly define either type of genetic redundancy.

      ...in one, changes at a single location in a gene's DNA often produces no actual or effectively no change in the coded protein.
      ...in the other, when crossing over is unequal, offspring may get "extra" copies of genes that can be altered for additional functions without affecting the gene's original purpose (which is done with the "non-extra" copies. 

 

2. What are two different, specific ways that materials can get across a cell membrane? (Not looking for why they move, but rather how they get through)

DIFFUSION

CARRIERS / ACTIVE TRANSPORT

3. Briefly describe two distinctly different ways that gender is determined in animals.

1 - UNMATCHED CHROMOSOME PAIRS (XX-XY)
2 - SINGLET - DOUBLET CHROMOSOMES (XX - X)

3 - GENETIC RESPONSES TO ENVIRONMENTAL CONDITIONS

4. Define syncytium.

      ...a multinucleated "cell" (from multiple mitosis without cytokinesis or fusion of cells)

 

5. What are two different ways that a population can, over time, respond to a change in environment?

1- Go extinct
2 - Survive with no or minimal change

3 - Survive with distinct change(s)

6. What critical feature does a hypothesis require in the Scientific Method?

      ...there are two possible - it should be predictive and testable.

 

7. In what circumstances do animals evolve a resistance to change?

      ...if they are well-suited to an environment that is extremely stable over long time periods, they "settle in" to this successful form and resist changes.

 

8. Briefly explain what it would mean if features from two animal species are analogous but not homologous.

      ...they are used for the same function but their basic construction is very different.

 

9. Translate into modern English: "Ontogeny recapitulates phylogeny."

      ...embryological development mimics evolutionary history.  An embryo "replays" its family tree.

 

10. Why are there so many gaps in the fossil record?

      ...most fossils are remnants of sediments from bodies of water, but many land areas were previously water body bottoms only intermittently in the past.

 

11. Briefly explain an approach to comparative biochemistry that does not involve molecular sequences.

      ...comparison of metabolic molecules, in specific function and basic construction / derivation.

 

12. Give two entirely different types of facts about the pH scale.

There are a bunch:
- based upon Hydrogen Ion Concentration
- numbers are from negative exponents of concentration
- acids have more H+, bases more OH-
- each unit change is a tenfold change in strength

- 7 is neutral;  below is acidic;  above is basic
- is based on the tendency of tiny concentrations of water to separate into ions

13. Briefly explain why the role of chance has to be an important consideration in evolutionary biology.

      ...both mutations and environmental change are chancy, as are whether there will be individuals around that can deal with a particular change.

 

14. For an electron microscope (in comparison to a light microscope), give one each -

Advantage

- has greater resolution
- can produce a range of beam sizes

Disadvantage

- more expensive
- more difficult to use
- requires vacuum for beam 

15. For a low chromosome number, give one each -

Advantage

Sorting for cell division is more efficient

Disadvantage

Produces less variation in off spring

 

16. Mendel’s Law of Independent Assortment later had to have an exception inserted into it. What is the exception?

      ...it does not work if genes are linked

 

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.
Six Points Each. Partial credit is possible.

1. Describe (don’t just use a term) the two ideas about evolution that are generally linked to Lamarck.

Parents can pass on traits they have acquired during their lifetime.

Evolution is a series of improvements leading to "better" forms.

2. Name and give the basic function of three different cytoplasmic (non-nuclear and non-external) eukaryote cell organelles.

MITOCHONDRIA 

Aerobic Respiration

ENDOPLASMIC RETICULUM

Channel Network for moving things

GOLGI BODIES

Production of Secretions

RIBOSOMES Protein Production
LYSOSOMES Carry Digestive Enzymes
VACUOLES Store various things
CHLOROPLASTS Photosynthesis (not an animal organelle, but still answers the question)

3. What are three matched pairs of differences between

FLAGELLA

CILIA

 LARGER

SMALLER

RARELY MORE THAN 12 ON CELL

ALWAYS NUMEROUS ON CELL

MAY HAVE ADDED STRUCTURES

DON'T HAVE ADDED STRUCTURES

TEND TO SPIN TEND TO STROKE

4. Number the following steps in the order that the current Heterotroph Hypothesis puts them:


__7__ Cambrian Explosion
            Rise of animals had to follow most
             of the other steps.


__2__ Formation of Primordial Soup
           Right after the Earth formed and
            cooled.


__5__ Evolution of Eukaryotes
            After all of the important stuff
             appeared in prokaryotes.


__6__ Evolution of Multicelled Organisms
            Something only eukaryotes seem
             capable of doing.


__1__ Formation of Earth 
           Kinda has to be first...


__4__ Evolution of Aerobic Respiration
            Requires oxygen, which requires
             photosynthesis, which requires
             autotrophs.


__3__ Evolution of Autotrophs
            After the early cells began to use
             up the soupy food.


__8__ Movement of Life Onto Land
            The last major step - everything else
             was done in the oceans.

5. Name, in order of increasing complexity, the organizational levels found in most multicellular animals.

Cytoplasmic

Organs

Cells

Organ Systems

Tissues

Organism

6. What are six distinct features / functions associated in general with things that are alive? These would apply to more than just animals.

 UNIQUE CHEMISTRY  (DNA & Protein- Based)

HIERARCHICAL ORGANIZATION  (As seen in the question right above!)

REPRODUCTIVE (Able to pass traits to offspring)

METABOLISM  (Chemistry uses & transforms energy)

DEVELOPMENT / GROWTH (Life Cycles)

INTERACTIONS WITH ENVIRONMENT

ABLE TO EVOLVE

7. For three requirements of the Hardy-Weinberg Law, name the requirement and describe an evolutionary process that depends upon breaking that requirement.

NO NATURAL SELECTION

Natural Selection

RANDOM MATING

Sexual Selection

LARGE POPULATIONS

Bottleneck Effect

NO MIGRATION Founder Effect
NO MUTATIONS Genetic Redundancy

 

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.

 

Carbohydrates serve a critical function in plants that they rarely do in animals. What is it? Three Points.

 

 

What remnant in the fossil record shows when photosynthesis really "took over"? Three Points.

 

 

Which human tissue is a syncytium? Three Points. Three Points for another example.

 

 

Why did Mendel work on pea plants? Three Points.

 

 

Uniformitarianism was an idea that disagreed with what popular ideas of its time? Three Points Each.

 

 

Give up to two reasons, for Three Points Each, why Darwin and not Wallace has gotten almost all of the credit for their idea.

 

 

Other than evolutionary biology, what discipline is Wallace considered the father of ? Three Points.

 

 

What non-biological discipline did Hardy and Weinberg work in? Three Points.

 

 

 

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