BI 171 Exams - First Exam 2000

BI 171 - First Exam - 2000

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.

___D___ 1. When comparing a solution of pH 13 to one of pH 11, the pH 11 solution is
                        a. Twice as basic
                        b. Twice as acidic
                        c. 100 times more basic
                        d. 100 times less basic
                        e. Not as tasty

...each step on the scale is a tenfold change - 2 steps is 10 x 10, or 100.
steps moving inward toward 7 are reductions in strength

___A___ 2. Which type of molecular bond has the smallest role in living systems?
a. Ionic b. Polar c. Covalent d. Hydrogen e. Super Glue

...since water disrupts most ionic bonds, they have a limited role -
the separated ions have big roles.

___C___ 3. Hypotheses can be tested by
                        a. Repeating the initial observation many times
                        b. Deducing their implications
                        c. Confirming a hypothetical prediction
                        d. Finding a logical link to an existing theory
                        e. Making sure that they rhyme

...hypotheses should be predictive and testable.

___A___ 4. In general, the theory of evolution by natural selection
                        a. Starts with individuals but works in populations
                        b. Proposes a process independent of the ecosystem
                        c. Starts with populations but works on individuals
                        d. All of the above
                        e. Was confusing enough before this question was written.

...individuals are "selected," but over time it's the impact of that on the
population that changes the basic "type."

___D___5. Which of these would include predators and prey but not snowfall?
a. Species b. Ecosystem c. Population
d. Community e. Nature walks in summer camp

...a and c are just single types - predators and prey are two - and b
includes physical factors like snowfall. Process of elimination.

___C___6. When scientific method is said to be systematic, that means it is
                        a. Periodically reviewed by governing bodies
                        b. Always moving forward
                        c. Run by standard rules
                        d. Linked to logic
                        e. Stuck with an a tic in its systems, which can be really painful

...the "system" here is internal - the rules it runs by

___B___7. Row 3 of the Periodic Table reads, from left to right, Sodium, Magnesium,
                    Aluminum, Silicon, Phosphorus, Sulfur, Chlorine, and Argon. In what form is
                     Magnesium most likely to exist in Nature?
                        a. Uncharged                 b. A +2 ion             c. A -2 ion
                        d. There's no way to tell                 e. A big rock

...Column 2 means the most stable form has lost 2 (negative) electrons,
leaving behind two unbalanced (positive) protons

___A___8. A human eye and a video camera could be said to be
                        a. Analogous only             b. Analogous and homologous
                        c. Homologous only          d. Neither analogous nor homologous
                                    e. A strange thing to compare in any case

...they have similar functions, but not similar underlying structure.

___A___9. In evolution, new traits are most likely to be
                        a. Produced by mutations                     b. Advantageous
                        c. Modifications on existing traits          d. Totally heritable
                                                e. Preferred by consumers

...mutations do this, but rarely. The traits aren't necessarily going to be
good or, in sexual reproducers, something passed on intact.

___B___10. Carrying capacity always acts as a limiting factor, or brake, on
a. Fitness b. Population growth c. Evolution
d. Adaptation e. I know, I know! ...How much can be carried, right -?

...it's how much the local ecosystem can "carry" of a population.

___B___11. The idea, drawn from fossils a couple of centuries ago, that many types of
                        animals had gone extinct, most challenged what assumption drawn from
                        the Bible?
                            a. No evolution had occurred          b. Creation of perfect types
                            c. A young Earth                             d. Human dominion over Nature
                                e. That snakes couldn't be trusted with women (or vice versa)

...how could things designed by God for Eden have been flawed enough
to go extinct?

___A___12. In a population, what is the order from largest to smallest?
                        a. Gene pool --> genome --> gene
                        b. Genome -> gene pool -> gene
                        c. Gene -> gene pool -> genome
                        d. Genome -> gene -> gene pool
                        e. Who am I, Goldilocks??

...right out of the notes: population - individual - piece of individual.

___A___13. A small population is more affected than a large population by
a. Chance b. Ecosystem factors c. Competition
d. Reductionism e. Nasty jokes

...an "accidental" event affects a bigger fraction of a small population than
a large population

___B___14. Which term most closely connects to the mistake of expecting all dogs to
                        be like one particular dog?
                            a. Lack of control                 b. Anecdotal evidence
                            c. Indirect observation          d. Emergent properties
                                                e. Poochie problems

...too small a study group to remove the influence of chance.

___D___15. Liquid water is most dense
                            a. At its freezing point, 0^oC             b. At its boiling point, 100^oC
                            c. It's always equally dense              d. At 4^oC
                                    e. In the brains of exam-taking biology students

...the molecules get closer together as water cools until, at this temp,
their partial charges start to repel and push them apart

___D___16. Industrial espionage often involves reverse engineering, taking a stolen
                        device apart and, by analyzing each piece, figuring out what the
                        device does. This is like the scientific process of
                            a. Experimentation             b. Uniformitarianism
                            c. Homologous traits          d. Reductionism
                            e. Hitting things with a hammer and giggling uncontrollably

...this is just an application of the principle.

___A___17. Carbon dating uses
                        a. Radioactive isotopes to determine the ancientness of biological materials
                        b. The bonding properties of carbon to determine an organism's age
                        c. The breakdown ratio of water and DNA
                        d. Rates of electron loss to neutron number
                        e. One of the Internet's weirdest chatrooms

...just a matter of recognizing something from the notes.

___B___18. In the process of evolution by natural selection, the role of the environment
                         is to
                            a. Stimulate the mutation of certain genes
                            b. Increase the reproductive rate of certain members of a population
                            c. Create particular adaptations needed at that time
                            d. Enable the population to evolve toward a predetermined goal
                            e. Get in the way as much as possible

...the remaining choices are very Lamarckian.

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. What are two ways that two species can occupy essentially the same niche in the same area?

They occupy it at different times of day

Could also be local physical separations- ground-level to tree-level, for instance, or neighboring lakes.

They occupy it at different times of year.

2. Which Kingdoms (out of the book's five) include groups that are photosynthetic?

Monera, Protista, Plantae

3. What are four key, essentially separate subfields of biology that are seeing great status and funding?

Molecular Biology, Genetics, Embryology, Ecology, Immunology, Neuroscience...

4. In general, what sort of traits do you believe are most significant to an organism's evolutionary success (there's more than one answer to this), and give a brief reason why you think that sort of trait is the most significant.

There are a number of answers - ability to cope with changes in climate, or new diseases, or changes in nutrient availability and possible. Ability to replace lost members or spread offspring across wide areas, too, and a lot of others - anything that is reasonable and fairly general.

5. Briefly explain what a hydration shell is.

When water molecules surround ions, atoms, or molecules, "sticking" on by their partial charges and allowing them to dissolve.

6. What are the two most important features of an experiment as far as reproducibility is concerned?

Terms must be clearly defined.

How data will be collected and assessed.

7. Briefly explain the nature of the double bond in O₂.

Uncharged Oxygen atoms have 6 valence electrons, 2 shy of a stable 8. Two Oxygen atoms each share 2 of the other's electrons - double bond - to add those two and stabilize themselves.

8. Briefly define an ecological niche.

It's a role played by a type of living thing in an ecosystem.

9. What are two totally different ways that traits can be "handed down" to offspring?

By DNA, by teaching, by "inheritance" almost as humans define it (such as in territory).

10. Give a brief example of artificial selection.

Breeding to develop a new kind of (any kind of domestic organism)

11. Briefly explain what is meant by:

EMERGENT PROPERTIES

Produced by an unpredictable or non-reducible combination of traits - a bunch of pieces together do something that isn't just an additive effect of the pieces.

12. What is the latest, currently-accepted definition of a species?

A group of organisms that, under natural conditions, only reproduce within their group.

13. What is the primary weakness, evolutionarily, of sexual reproduction?

It is impossible to exactly reproduce a single well-adapted individual.

14. In what way were Darwin's evolutionary principles uniformitarian?

They assumed evolution worked slowly over long periods of time.

15. In an ecosystem, what is an invasion?

New species are brought in from outside and displace resident species from niches.

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. Pick three people responsible for three different important biological ideas. Give the person's name in the first column and the basics of the idea in the second. When two or more people are linked to the same idea, you only have to name one of them, but don't use the idea more than once.

LaMarck	Evolutionary changes could be explained by passage of advantageous traits
Darwin	Evolution by Natural Selection
Wallace	Natural Selection, "forced" Darwin to publish
Malthus	How populations are controlled by "natural" forces
Hardy-Weinberg	What factors affect evolution in a population

2. Name three different properties of water and for each, briefly explain a role that property plays in biological systems (this could be an example).

Dissolves many types of molecules & ions	Makes it an ideal support medium
Cohesive	Makes it resistant to temperature changes and evaporation
Adhesive	Useful in filling spaces inside organisms
Expands upon freezing	Bodies of water tend to not freeze solid

3. The theory of evolution by natural selection is based upon several principles, easily-acceptable features of Nature that lead to the theory itself. What are four such principles?

More offspring are produced than will survive to make their own offspring.

There are variations among the individuals in a population.

Variations can be passed on to offspring.

Some variations will be favored in certain environments.

Individuals with advantageous variations will be more likely to survive and reproduce.

If a certain trait is favored, that trait will be more common in succeeding generations.

4. What are the four major themes of Biology, according to the book and notes?

Organisms are genetic systems	Organisms exist as parts of ecosystems.
Organisms evolve.	Organisms work through interactions on the molecular level.

5. Answer the following using the box below from Column 7 of the Periodic Table of Elements.
For the most common isotope...

18.99840

F

Fluorine

9

HOW MANY...

Protons?____9___                                                 Neutrons?___10____
       Equal to Atomic Number.             Atomic Weight (18.9984 ROUNDED OFF = 19)
                                                                                        minus 9 protons.

Electrons?____9____
        Equal to proton number (unless an ion)

Valence Electrons?_____7_______
                                 From Column Number

6. Name four conditions under which an allele's / gene's proportion in a population will not vary over time.

This is Hardy-Weinberg:

No Selective Advantages.
Random Mating.
No mutation.
No genes enter or leave.
Population is large.

7. Fill in the following for asexual reproduction:

Basic Definition:	Offspring are genetic copies of original.
Evolutionary Strength:	Advantages can be exactly passed on.
Longterm (evolutionary) Strategy for Success:	Large numbers of offspring needed. (This produces some needed variation and tends to spread offspring beyond many local effects.)

NO KEY FOR BONUS QUESTIONS.

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.

A current sociological trend, postmodernism, sees science from what perspective? Four Points.

Which key biology subfields consist largely of advanced math? Three Points each.

How a) is vestigial commonly defined (Two Points), but b) what does it often turn out to be? (Three Points)

If the species of Galapagos Island iguanas began as "castaways," what aspects of the initial journey might have "preselected" individuals for their island existence? Three Points each.

What features of viruses "break the rules" and make them difficult to consider as living? Three Points each.

What is it exactly about the different types of radioactivity that makes one type more or less dangerous than another? Four Points.

Water is commonly used in hydraulic systems because it is essentially incompressible. Why would this be true? Four Points.

Briefly, what was the handout on "the Mark of Cain" about? Five Points.

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