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BI 171 - First Exam - 2001
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. The chemical reactivity of an atom is most influenced by the number of...
a. Protons
b. Neutrons
c. Outermost electrons
d. Total electrons
e. Beers it's had
...it's only the outer layer of electrons that are available to react
___D___ 2. If Drano has a pH of 12 and Liquid Plumber has a pH of 11, then
a. Drano is twice as acidic than Liquid Plumber
b. Drano is twice as basic than Liquid Plumber
c. Drano is ten times more acidic than Liquid Plumber
d. Drano is ten times more basic than Liquid Plumber
e. Drink up, everybody!
...Drano's number is higher, so it's more basic, and each unit shift is
a tenfold change in strength
___B___ 3. The bones of a human arm and a front dolphin flipper have the same basic bones,
different only in layout and use. The arm and flipper are
a. Analogous only
b. Homologous only
c. Both analogous and homologous
d. Neither analogous nor homologous
e. Both tasty with the right sorts of seasonings
..."same basic bones" = homologous; "Different
in...use" = not analogous
___A___ 4. Ionic bonds are rare in biological systems because of what feature of those
systems?
a. Water content
b. Salt content
c. Presence of DNA
d. Presence of oxygen
e. Rampant ion discrimination
...it's difficult to hold ionic bonds together in water
___B___5. If Alfred Russel Wallace had not existed, Charles Darwin
a. Would have never come up with his Natural Selection theory
b. Might never have published his Natural Selection theory
c. Would have left out what became key details of his Natural Selection theory
d. Would never have made the trip that led to his Natural Selection theory
e. Would only be remembered for his wacky practical jokes
...Darwin had held off publishing for years, and only did so to get some
credit
for his ideas that his friends knew he had had long before but the
public didn't
___B___6. Which best describes the purpose of control tests?
a. To remove the variable and get the same results
b. To figure out how factors beyond the variable affect results
c. To repeat the procedures several times
d. To always produce clear results
e. This is too much of a lose control test to be sure
...a defines a classic control test, but the question asks
for their purpose
___A___7. A niche in the same geographical region can still vary due to
a. Time factors
b. Functional differences
c. Genetics
d. Its occupants
e. The way it's scratched
...the same function can be performed by different organisms at
different
times of day or in different seasons, which produces the variation in
the niche itself. This one's probably too confusing.
___C___8. A hypothesis is only useful to science if it is
a. A brand new idea
b. Widely accepted
c. Predictive
d. Restricted to one field
e. Accompanied by a fistful of cash
...without predictions, you can't "do" much with it
___A___9. The carrying capacity of an ecosystem would usually be most influenced by
a. Available food
b. Disease patterns
c. Amount of room
d. Available mates
e. Number of pockets
...how many of any organism can exist in an area is very tied to
what
nutrients are there
___C___10. Fluorine is found in Column 7 of the Periodic Table, which means it is likely
to form
a. Positive ions
b. Covalent bonds
c. Negative ions
d. Hydrogen bonds
e. Into really loud heavy metal "hair" bands
...Column 7 tells you there are 7 electrons in the outer shell, 1 less
than the
stable number of 8. Adding 1 electron to the 7 gets the atom to
the stable
number but gives it an extra negative charge
___D___11. You run a nutrition experiment on yourself. What term is most likely to be applied
in a critique of your experimental design?
a. Analogous
b. Emergent property
c. Homologous
d. Anecdotal evidence
e. Liability insurance
...that's the term for single-case or very limited evidence, a bad thing
___A___12. Isotopes of an element vary most in
a. Number of neutrons
b. Number of electrons
c. Number of protons
d. Number of neutrinos
e. Style and elegance
...changes the atomic weight and atomic stability but keeps it the same
element
___C___13. The founder effect is used to explain
a. New theories in science
b. Molecule formation
c. Gene ratios in a population
d. Control issues in an experiment
e. I think right now I'm experiencing the flounder effect...
...even if you just remembered only the heading this showed up under,
that
would lead you to this answer
___A___14. Which element is most likely to be involved in a double bond?
a. Column 6
b. Column 2
c. Column 7
d. Column 8
e. One in a column
...or, what needs to borrow 2 electrons to stabilize an outer shell to
8?
___B___15. Most of the current "hot" fields in biology involve study of
a. Classification
b. Molecules
c. Physics and mechanics
d. Behavior
e. Smelly furry animals
...it reflects the sophistication of the field, focused on the very tiny
___A___16. Avogadro's Number represents the number of
a. Atoms or molecules in a mole
b. Cells in the human body
c. Species on the Earth
d. Genes in the human genome
e. Students driven crazy by questions like this
...just one of those defined terms from the notes / book
___D___17. Which fundamental Biblical idea was first challenged when fossils of extinct
animals were discovered?
a. Man descended from Adam and Eve
b. Age of the created Earth
c. Earth as the center of the solar system
d. Modern Nature is a continuation of life created for Eden
e. Angels aren't highly mutated starlings
...remember, to people at the time, the Bible told them that Eden's
animals
were perfect creations of God and could not have gone extinct
___B___18. An hypothesis should be testable through
a. Experiments and controls
b. Experiments and controlled real-world observations
c. Statistical manipulations
d. Controls and variables
e. Seeing if it anyone gives a hoot
...these are the two different approaches to testing
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. Give two features of viruses that cause some biologists to consider them not living?
There are several, some better than others: They have no
metabolic chemistry when between hosts; many are not cellular; they have almost no
reproductive machinery of their own; free of the host, they cannot
react to changes in their environments; they neither grow nor go
through developmental stages.
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2. For the two classes or types of observations, give
| General Type |
Real-world example |
General Type |
Real-world example |
Direct |
Anything involving info coming in through your personal senses |
Indirect |
Anything second-hand, from other people or some sort of device |
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3. First, define artificial selection.
Domestic organisms are selectively bred for certain desired
traits which produces new "breeds"
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Then, explain how it influenced Darwin's
ideas.
If domestic organisms could be changed this way, so could wild
organisms - just the method of selection had to be found
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4. Briefly explain how science often works through reductionism.
This is the idea that by analyzing all of the small workings
within something, you can completely determine how its major
functions happen
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5. What are two features of the Earth that have led to the gradual "extension" of calculations of
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its age?
Layer after layer of sedimentary rock left over from
ocean sediments.
Evidence of continental drift.
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Evidence of wave after wave of living things that
go extinct and get replaced.
Radioactive breakdown products in the rocks that
needed huge periods of time for production. |
6. Put this alphabetical list in order from smallest to largest, ecologically: community, individual,
population, species.
| 1 Individual |
2 Species |
3 Population |
4 Community |
7. Briefly explain how Lamarck thought that evolution progressed.
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There are 2 aspects, but the first is the most important, that
changes (improvements) gained by organisms during their lifetimes
could be passed on to offspring.
The other is that evolution really was progress, that it had a set
direction and a goal of reaching God's perfect plan (us).
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8. Give two circumstances or factors that would prevent an experiment from being reproducible.
The question is, how can you set up your
experiment so that someone else wouldn't know enough to copy it?
It can be using badly defined terms, or vague measurements, or vague
procedures, unclear data-collection methods, lots of things.
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9. What is meant by an unused niche?
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This happens when an ecosystem has a "job"
available, but there is no species actually doing that job.
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10. What two factors have the most effect on evolutionary rates?
Rate of environmental change.
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Rate of reproduction. |
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11. In the absolutely purest sample of water possible, what contaminants have to be there?
In even absolutely pure water, .0000001 consists of H+ ions and
OH- ions.
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12. Briefly explain how the concept of types has influenced thinking in Biology for centuries.
The idea of types, with their set reliable labels underlies the
idea of classification in groups, the overall progress of evolution,
and even modern ecological ideas.
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14. Define what would be meant as your personal genome.
This would be the makeup of all of
your individual DNA.
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15. Sexual reproduction has a huge evolutionary advantage over asexual reproduction.
What is it?
It produces greater variety (and
adaptive flexibility) in offspring.
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16. Briefly define uniformitarianism.
The world of the distant
past worked essentially as it does today, and any differences arose
and changed very very gradually
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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. Modern biology is based upon four major themes that describe the patterns followed by all living
things. What are three of those themes?
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GENETIC SYSTEMS, working with an informational system that determines
type and can be passed down. |
ECOSYSTEMS are the supporting structure in which living things exist
and interact.
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EVOLUTION allows adaptation to conditions and changes the nature of
living things over time. |
MOLECULAR INTERACTION is the driving force in biological existence.
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2. Answer the following using the box below from Column 2 of the Periodic Table of Elements.
For the most common isotope...
HOW MANY...
Protons?___15___
Neutrons?___16___
Matches the atomic number.
"Leftover" when protons are subtracted
from atomic weight of 31 (30.97176
rounded off).
Electrons?____15___
Outer Valence Electrons?______2______
For regular atom (not
ion),
same
Matches Column Number
as proton number.
3. Fill in the following for asexual reproduction:
Basic
Definition: |
Offspring are genetic
copies of "parents." |
Evolutionary
Strength: |
Allows exact
reproduction with very rare changes. |
Long-term
(evolutionary)
Strategy for Success: |
To avoid being killed
by new, inhospitable environments, offspring numbers must be huge to:
a) produce some adaptive variety from rare mutations, and b) spread
offspring widely enough so they won't all be caught in changes |
4. What are three basic principles of Darwin's Theory of Evolution by Natural Selection?
Variety of individuals in a group give some advantages in certain
environments.
The ones with advantages are more likely to survive and
reproduce. |
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An increasing fraction of following generations will show the traits
of the advantaged forms as long as the environment persists. |
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Over time the basic "type," or species, will change so much
from the ancestor as to be a new species. |
5. Name 3 properties of water related to its bipolarity and for each, explain how that particular
property is important to living things.
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SOLVENT |
Makes it the perfect support system
for the complex atomic workings of living things. |
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ICE LESS DENSE THAN LIQUID |
If ice sank when frozen, oceans would
have frozen from bottom up and probably never had thawed (among other
things) |
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COHESIVE |
Makes water stable across a fairly
wide temperature range for a liquid and keeps it around as a medium to
develop Life in. |
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There are other properties or variations on these and other ways that
they are important to living things. |
6. The Hardy-Weinberg Principle says, in effect, that no evolution occurs if certain things are
true about a population's gene pool. What are 3 of those things?
| No gene combinations produce
advantages in individuals.
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| Mating is completely random.
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| No genes enter or leave the
population.
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| No mutation occurs.
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| The population is very large.
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7. For the book's 5-Kingdom system, give the name of each and a list of one or more features
that, taken together, makes that Kingdom largely distinct from the others.
| MONERA
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Prokaryotes. |
| PROTISTA
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Single-celled Eukaryotes. |
| PLANTAE
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Multicelled photosynthesizers. |
| FUNGI
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Multicelled, heterotrophs, absorb
nutrients though outer surfaces. |
| ANIMALIA
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Multicelled, heterotrophs, absorb
nutrients through inner digestive cavity surface. Usually
mobile. |
THERE IS 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.
Briefly describe the content of the Cancer in the Crosshairs handout for Four Points.
If rigidly applied to the scientific method, many of Albert Einstein's idea about gravity being a
warping of space would be considered scientifically weak. For Three Points, explain why.
Classically, scientists make distinctions between hypotheses, theories, and laws. These
definitions were not covered in class, however. For Three Points, why not?
What is it about a small study sample that makes it unreliable? Explain, for Three Points - don't
just give an unexplained term.
For Four Points, give an example of an adaptation that is heritable but not genetic.
Briefly explain how flourescent lights work.
Four Points.
What is the "Snowball Earth" Theory?
Four Points.
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