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SC 139 - Second Exam 1999
ANSWER KEY
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. A non-scented green flower at the upper tips of a plant would most probably
___B___
a. Be pollinated at night
b. Be wind-pollinated
c. Be found on a fern
d. Be found on a moss
e. Be a failure on Valentine's Day
...no scent, no color usually means no pollinators, which usually means
pollen spread by the wind...
2. The first "living" molecules competed. What abilities would have made a
molecule a good competitor?
___D___
a. Finding mates & keeping space
b. Catching & eating others
c. Moving onto land & staying there
d. Gathering raw materials & reproducing quickly
e. Being able to make lower the other molecules' self-esteem
...no mating, a long way from land and probably too early to be eating,
only D is reasonable for molecules...
3. As plants have evolved, what has become the dominant form?
___A___
a. Sporophytes
b. Gametophytes
c. Ferns
d. Nonvascular
e. FTD Florists
...right out of the notes and book...
4. Pollinators and flowers have adapted to each others' needs through
___B___
a. Convergent evolution
b. Coevolution
c. Divergent evolution
d. Coadaptation
e. A complicated prenuptial agreement
...where two species adapt to each other...
5. A seed contains
___C___
a. Just a plant embryo
b. Pollen & pollen tubes
c. A plant embryo & food
d. All of these
e. Stuff that's good and good for you
...kind of equivalent to an egg...
6. Which is true about classification systems?
a. With enough evidence, a scientist can change anything he wants
b. Cladistics focuses on new traits, systematics on evolutionary connections
___B___
c. Systematics focuses on new traits, cladistics on evolutionary connections
d. Different arrangements are not allowed
e. The more confusing, the better
...out of the notes...
7. Spores are produced
___A___
a. Asexually by ferns
b. Asexually by gymnosperms
c. Sexually by ferns
d. Sexually by gymnosperms
e. By lots of creepy thingies in horror movies
...out of the notes / book...
8. The main purpose of fruit is to be
___B___
a. A food source for animals
b. A way to spread seeds
c. A food source for seeds
d. Protection for seeds
e. A source of Life Saver flavors
...just go with what you've been taught rather than what you used to
think...
9. A stromatolite is a
___C___
a. Spore producer
b. Pollen producer
c. Type of ancient fossil
d. Land animal
e. Great thing to have if your stromato is dark
...some of the earliest fossils known, of bacterial masses...
10. In angiosperms, where do pollen tubes first form?
___A___
a. Stigma
b. Anther
c. Seeds
d. Ovaries
e. In the tube tub.
...in the upper female parts, in order to reach D later and form C
much later. Pollen is made in B, but not the tubes...
11. What term is given to the sprouting of a "baby" plant from a seed?
___C___
a. Pollination
b. Flowering
c. Germination
d. Pioneering
e. Peeping out
...just one of terms you're supposed to know...
12. Modern land plants probably could not have made that first move
out of
the water without
___B___
a. Pollen
b. Fungus symbionts
c. Woody stems
d. Pollinators
e. A forwarding address
...right out of the notes...
13. The organic materials of the primordial soup came from
___A___
a. The Earth's starting materials
b. Autotrophs
c. Heterotrophs
d. Fungi
e. Campbell's
...it was there when the oceans formed, everything else was much
later...
14. Which are female flower parts?
___C___
a. Petals & pistils
b. Stamens & anthers
c. Stigma & Pistils
d. Petals & anthers
e. Should we be discussing such things?
...just remembering the names...
15. From which environment did organisms probably move onto land?
___D___
a. Tidal pools
b. Fresh water
c. Estuaries
d. All of these are likely
e. Wet
...C is a combination of A and B...
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.
1. What is it particularly about pollen that made it such a great development in the evolution
of land plants?
...it freed sexual reproduction from needing "open" water to
carry the sperm, which opened a lot of new possible environments...
2. Briefly outline the Gaia Hypothesis.
...the living things on the earth, as a group, help stabilize the
environment, acting as a sort of thermostat...
3. Define. (Don't identify by plant life cycle phase!)
DIPLOID:
Having two
sets of matched chromosomes
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HAPLOID:
Having only one
set of chromosomes |
4. Put them in order, SMALLEST TO LARGEST: Class, Family, Genus, Kingdom,
Order, Phylum, Species, Superclass.
| 1 Species |
2 Genus |
3 Family |
4 Order |
| 5 Class |
6 Superclass |
7 Phylum |
8 Kingdom |
5. Give an example of a bryophyte.
...includes mosses and liverworts...
6. The pacing of evolutionary change is probably both gradual and punctuated. Why?
...because it's dictated by how the environment changes, and that can
follow either pattern...
7. Give two environmental conditions that favor conifers over angiosperms.
...they do better in drier, colder, windier, or more nutrient-poor
environments...
8. Define alternations of generations.
...it's a life cycle that always has an asexual phase and a sexual
phase...
9. What are two sources of energy that were probably have been available to molecules
evolving in the Primordial Soup?
...could have been sunlight (especially ultraviolet), or hot chemical
energy, or lightning...
10. What are two different types of "bribes" a flower can produce to bring in pollinators?
...can offer food or a sexual partner...
11. Define pioneer organism.
...the first species to move into a newly-opened environment, kind of
paving the way for others to follow...
12. What happened during the Cambrian Explosion?
...all of the major groups of animals appeared in the fossil record over
a brief span of time...
13. Briefly explain the endosymbiosis theory. (You don't need to give technical terms)
...some modern cell parts were originally independent cells, taken in by
larger cells, "put to work" as helpers, and eventually losing
their nature as independent cells...
14. What structure will help tell a true fern apart from a ferny-looking angiosperm, and
where on the plant is that structure found?
...look on the undersides of the leaves for sori, the spore-producing
structures...
15. There was a big feature, hard to explain, about the first living things that the first
theories felt was absolutely necessary. Then the heterotroph hypothesis said otherwise.
What was the feature?
...since modern ecosystems depend on plants for fuel/food, early
theories felt that they had to explain how plants appeared as the
first living things, but plants are too complex for that to be
easy. The heterotroph hypothesis says that, even with nothing
alive yet, there was fuel/food available in the primordial soup
from which very simple, then more complex, living systems could
develop...
16. What are two ways that male pine cones are different from female cones?
...they are usually smaller, higher on the trees, and smoother...
LONG ANSWER.
Answer any three of the following questions for Eight Points Each.
Note: if you answer more than three, only the first three will be corrected.
You can get partial credit on these answers.
1. What are four possible causes of mass extinction events?
Asteroid or Comet
Impact |
Ice Ages |
Continental drift connecting land masses
Continental drift producing major climate changes |
Major Volcanic Eruptions |
2. Number the following steps in the order that the current Heterotroph Hypothesis puts them:
| __3__ Evolution of Autotrophs |
__2__ Formation of Primordial Soup |
| __8__ Movement of Life Onto Land |
__7__ Cambrian Explosion |
| __4__ Evolution of Aerobic Respiration |
__5__ Evolution of Eukaryotes |
| __1__ Formation of Earth |
__6__ Evolution of Multicelled
Organisms |
After the Earth and Primordial Soup formed, chemical evolution is
leading to first "living" molecules, before cells, and leads
to protocells, which aren't even prokaryotes yet. Once prokaryote
cells had evolved, autotrophs (when the soup ran out) and aerobic respiration
(after autotrophs had released lots of oxygen) evolved before the
evolution of eukaryote cells, which were necessary before you could have
multicelled forms. The Cambrian Explosion happened while Life was
still stuck in the oceans, and much later did Life move out onto land.
3. Briefly describe (more than 1-2 words, please)
four different ways that life on land was
significantly challenging to water organisms evolving in that direction.
Had to resist drying out.
Had to support selves without water around them
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Had to tolerate faster
temperature changes
Had to tolerate much stronger sunlight
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Had to deal with much higher
oxygen levels
Had to develop ways to reproduce that didn't use water to spread
sperm.
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4. For four of the textbook's
five Kingdoms of organisms, give:
| Kingdom Name |
Trait(s) that make them clearly different from the other 4
groups. |
a. MONERA
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All you need here is that cells have
no nuclei. |
b. PROTISTA
|
Cells have nuclei, but that's not
enough (also true for c,d,e); also needs: group is mostly
single-celled forms |
c. FUNGI
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Multicelled (a & b have similar
single-celled forms); Heterotrophic, non-moving, absorb
nutrients through outside surfaces |
d. PLANTAE
|
Photosynthetic (not enough - also true
in a & b) and multi-celled |
|
e. ANIMALIA |
Multicelled, heterotrophic; consume
and digest food internally; usually can move |
5. Give four sets of clear-cut differences between...
| MONOCOTS |
DICOTS |
| Leaf veins are
parallel.
|
Leaf veins branch. |
| Root system usually
fibrous (highly branched)
|
Usually with taproot (One major root
with much smaller secondary roots) |
| Almost never woody
|
Has many woody species |
|
Flower parts in multiples of 3
|
Flower parts in multiples of 4 or 5 |
| Single-part seeds
|
2-part seeds |
Vascular bundle
patterns:
ring in roots, random in stems
|
Vascular bundle patterns:
central "X" in roots, ring in stems |
6. Give three sets of differences between the sex cells of:
| MALES (sperm): |
FEMALES (egg cell): |
|
Much smaller |
Much larger |
|
Produced in much greater numbers |
Produced in much smaller numbers |
|
Must somehow get to egg cell |
Must wait for sperm to find it |
NO ANSWER KEY FOR BONUS QUESTIONS.
BONUS QUESTIONS. 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.
The fellow who organized our current biological classification system had an odd habit.
What was it? Four Points.
What role might clays have played in the beginnings of Life on earth (other than that Adam
thing)? Four Points.
What two simpler systems might have combined at deep-sea hydrothermal vents to produce
photosynthesis? Five Points.
Give one major detail of classification over which the book and Mr. McDarby disagree. Four
Points.
What is "Nemesis?" Four Points.
What advantage did the development of alternation of generations give land plants? Five
Points.
What does "-phyte" mean? Three Points.
What sort of pollinator is likely to visit a red flower? Four Points.
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