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SC 139 - Second Exam 2003
MULTIPLE CHOICE.
On the line to the left, place the letter of the choice that
best answers the question.
Three Points Each. NOTE: "e" answers are never
the correct answer.
1. The main concept of the Gaia Hypothesis is
that
___D___ a. Life has disappeared
and reappeared on Earth several times
b. Life was originally a type of replicating clay
c. Life was the result of Special Creation
d. Life stabilizes the global environment
e. One should use vowels more than consonants
...especially in terms of temperature - carbon dioxide acting as a heat
blanket - but in water vapor and some
other atmospheric gases as well.
2. For a long time, biological theories about the origin
of Life on Earth from starting
molecules were hard to produce because it was thought that the first
major step would have to produce
___A___
a.
Plants b.
Animals c.
Dinosaurs d. Vertebrates
e. A story whose movie rights would bring in big bucks
...all life currently depends on plants for fuel, so they figured plants had to
be first - then it was realized that other energies, combined with
primordial soup, could get things started...
3. Which relies on fungal symbionts to live?
___D___ a.
Algae b.
Insects c.
Bacteria d. Land
plants e. Politicians
...the fungi pick up critical nutrients that the plants have trouble getting.
4. The first "living" molecule systems were most
probably what type of molecules?
___C___ a.
Protein b.
DNA c.
RNA d.
Water e. Squiggly.
...RNA can code and affect chemistry, done today separately by DNA &
proteins - but that specialization wouldn't work early on...
5. Most genetic mutations produce what sort of
effects?
___A___
a. None or
minimal
b. Bad - diseases
c. Good - improvements
d. None of
these
e. Weird laser effects
...most DNA changes miss important sections or, when they hit genes,
change the DNA without much changing the protein it codes for.
6. Which relates to ecospecies?
___B___ a. Parts of a food
chain b.
Same functions, different locations
c. Close relatives
d. Evolutionary partners
e. If it’s slimy: "Eeek! A species!"
...it's a loose definition of the term.
7. What is the function of a chloroplast?
___A___
a.
Photosynthesis
b. Digestion
c. Water absorption
d. Aerobic respiration
e. Producing complete confusion in students
...the resemblance to "chlorophyll" is not accidental.
8. What was the source of the organic materials in
primordial soup?
___C___ a. First
cells
b. First plants
c. Space dust
d. All of these
e. Well, was it a condensed soup, or more of a stew-?
...it needed to be there when the Earth first formed, so it had to come
from the materials the Earth formed from.
9. In today’s world, which is true?
___C___ a. Heterotrophs are the
base of the food chain
b. Both heterotrophs and autotrophs are the base of the food chain
c. Autotrophs are the base of the food chain
d. Primordial soup is the base of the food chain
e. Hey, as long as I get fed, I don’t care which link I am
...plants are the commonest autotrophs, and all of the heterotrophs'
fuel molecules can be traced back to autotroph producers.
10. Which are a typical feature of eukaryotes but not
prokaryotes?
___B___ a. Fungus symbionts
b. Membrane chambers
c.
Reproduction
d. DNA
e. Ummm, how come the answer I want isn’t here...?
...a isn't at all typical, and both groups have c and d.
11. When a mutation produces an extra copy
of a gene that can be used for
a new purpose while the "old’ gene keeps producing its original
protein, this is called
___A___
a.
Redundancy
b. Replication
c. Genetic drift
d. Adaptive
duplication
e. Xeroxification
...match the definition to the term.
12. When primordial soup molecules went through chemical
evolution, what did they compete for?
___D___ a. Protection from
parasites
b. Space
c. Water
d. Raw materials
e. A chance to sing on American Idol
...remember, they're molecules, there's not much they can actually use...
SHORT ANSWER.
Answer any eight of the following
questions for 4 Points Each.
Note: if you answer more than eight, only the first eight will
be corrected.
You can get partial credit on these answers.
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1. What are two different types of molecules whose sequences
are compared when biologists are trying to determine evolutionary
relationships between species? |
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DNA or RNA (same basic type)
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Proteins
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2. Define sexual selection in evolutionary terms.
...those
with traits that make them successful in getting mates are most likely to
send such traits on to offspring.
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3. The first photosynthesis systems were most likely a combined
form of which two pre-existing systems? |
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CHEMOSYNTHESIS (Fuel
production using hot chemical energy) |
LIGHT SENSING
(To stay around glowing hydrothermal
vents)
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4. What were most likely the "staging areas" from
which animals evolved into land forms? |
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TIDAL POOLS
(Changing dilutions, temperatures,
sun exposure, etc) |
FRESH WATER
(Waterproofing necessary, changing
temperatures, crawling, sun exposure, etc.)
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5. Briefly explain the endosymbiont theory.
...a
couple of cell organelles (mitochondria, chloroplasts) probably are
evolved from ancient independent cells taken in by bigger cells, which got
more benefit (aerobic respiration, photosynthesis) from keeping them alive
than from simply digesting them.
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6. What is the advantage of a low chromosome number?
...fewer chromosome errors occur when cells divide.
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7. During the era of primordial soup, what are two different
energy sources that could have been used to construct complex
molecules? There are more than 2... |
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Ultraviolet
Hot chemicals from magma
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Lightning
Light
Energy holding small molecules together
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8. What sort of material would have formed the first "membranes"
of the first protocells?
...lipids, or oily materials floating on the primordial soup.
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9. Briefly explain panspermia.
...it's the idea that Life originated on an older, destroyed world, but
survived on meteors which carried it to the early Earth - we got it
"ready-made."
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10. Define alternation of generations without using the words
"alternate" or "generations."
...it's
a life cycle that always involves both a sexual reproduction stage and
an asexual reproduction stage. (Reproduction "generates"
offspring, and this back-and-forth is the alternation)
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11. Give two different types of examples of
epigenetic traits. This is anything parents
can pass on to offspring that isn't part of the genetic package.
They include... |
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Things taught.
Status within a group.
Diseases, sometimes.
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Location / territory.
Physical features / inclusions of cells (single cells) or sex cells
(sexual reproducers)
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12. What is meant by chromosome linkage?
...it's when genes are physically "riding" on the same
chromosome, they're all part of the same single piece of DNA (and linked
alleles generally get passed along as "packages").
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13. Briefly explain what happens to bring about a founder effect.
...a
small group from a population migrates away and gets isolated (from there,
they evolve, but only can use what mix of alleles they brought with them).
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14. What are two ways that the primordial soup Earth
environment was significantly different than the Earth today? There
are more than 2. |
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-NO LIFE-
-NO OXYGEN-
-MORE VOLCANIC ACTIVITY-
-MORE METEOR IMPACTS-
-MORE STORMY ATMOSPHERE-
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-NO PROTECTION FROM ULTRAVIOLET-
-OCEANS FULL OF SMALL ORGANIC MOLECULES-
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LONG ANSWER.
Answer any four of the following
questions for Eight Points Each.
Note: if you answer more than four, only the
first four will be corrected.
You can get partial credit on these answers.
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1. Describe (don’t just give a one-word
label!) four different types of isolation that can lead
to evolution of different species from the same ancestral group. |
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PHYSICAL ISOLATION BY GEOGRAPHIC
BARRIERS (Water bodies, deserts, mountains, etc.) |
ISOLATION BY TIME (In the same place,
different groups become active at different times of day, or seasonal
activity alters)
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ISOLATION
BY NICHE (In the same place, different groups start to work different
roles) |
ISOLATION BY BEHAVIOR (Especially
reproductive behavior - different groups with different preferences in
things like displays, etc.
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| ISOLATION
BY ALLERGY (Certain females reject certain males' sperm or
embryos they produce) |
ISOLATION BY ANATOMY (Changes in
sexual anatomy make mating between certain groups difficult or impossible)
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2. Answer the following about asexual reproduction - |
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Definition - Offspring are genetic
copies of the original (not necessarily physical copies!)
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Disadvantage, compared
Large groups of offspring have the same weaknesses - if a local
to sexual reproduction -
change hurts one, it's likely to hurt all of
them.
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Adaptation that "balances Producing
huge numbers of offspring - some variation comes
out" the disadvantage - from
occasional mutations, and population often spreads beyond
local effects.
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3. Describe four different features about the land environment
that would have presented major challenges to organisms evolving from
water ecosystems to land. There are more than
4. |
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WATER EVAPORATES INTO THE AIR FROM
CELLS |
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TEMPERATURES FLUCTUATE WIDELY &
QUICKLY |
DIRECT
SUNLIGHT CAN DAMAGE MOLECULES |
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OXYGEN LEVELS ARE MUCH HIGHER THAN IN WATER
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| AIR
DOES NOT SUPPORT PHYSICALLY AS MUCH AS WATER DOES |
| SEXUAL
REPRODUCTION BY SWIMMING SPERM NOT SUPPORTED |
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4. What are four conditions, according to the Hardy-Weinberg
Law, under which the allele frequencies in a population will stay
the same? |
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NO NATURAL SELECTION |
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NO MUTATIONS |
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RANDOM MATING / NO SEXUAL SELECTION |
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NO MIGRATION IN OR OUT |
| POPULATION
IS VERY LARGE |
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5. According to the heterotroph hypothesis, what is the most
likely order in which the following things appeared on Earth? Number
from 1 to 8 to the left of the terms. |
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Cambrian Explosion
7 - RISE OF ANIMALS, STILL IN OCEAN |
Eukaryote Cells
5 - AFTER THE MAJOR SYSTEMS WERE DEVELOPED
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Photosynthesis
4 - IN ACTUAL CELLS, BUT STILL PROKARYOTES |
Movement onto Land
8 - LAST MAJOR STEP |
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Multicelled Organisms
6 - NEEDS EUKARYOTE CELLS FIRST |
Primordial Soup
1 - FIRST THING NEEDED |
Protocells
3 - CONTAINMENT OF SIMPLE MOLECULE SYSTEMS |
Chemical Evolution
2 - OF MOLECULES IN THE SOUP |
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6. The very first living things would have needed some basic
traits to be considered "living... |
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Two traits needed in the
early molecule systems
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REPRODUCTION - SUCCESSFUL FORMS
HAD TO BE ABLE TO COPY THEMSELVES |
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METABOLISM (Maybe)
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EVOLUTION - FORMS NEEDED TO BE ABLE TO CHANGE
OVER TIME
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Two traits that weren’t
needed at first, but had
to appear before long
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CHEMISTRY BASED ON PROTEINS |
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CODING SYSTEM BASED ON DNA
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CELLS |
BONUS QUESTIONS. NO KEY FOR
BONUSES.
Answer as many as you are able. Wrong answers will not result
in points being lost from the main exam. You can get partial credit on
these answers.
If a biologist is trying to determine the gender (male
or female) of an organism or structure, animal, plant, fungus, whatever, what
particular feature has to be checked? Three Points.
What is it about sharks that makes them very resistant
to cancer? Three Points.
The northern end of the original mountain chain that
includes the Adirondacks ends where today? Three Points.
What scientist is considered the "father" of biogeography?
Three Points.
Some of the world’s oldest fossils are found locally
- where? Three Points.
The spread of photosynthetic organisms across the
oceans left what sort of mark in the fossil record? Three Points
During the Age of Dinosaurs, the dinosaur-like animals
that lived in the oceans were really what sort of reptiles? Three Points.
Which groups are often thought of as the last surviving dinosaurs? Three
Points.
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