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SC 139 - Second Exam 1998
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. Why is it thought that the development of DNA was a very early
development
in the history of Life on Earth?
___C___
a. It can be found in the oldest fossils
b. Only DNA could have been the first "living" molecule
c. Every living thing known uses it
d. It isn't - DNA is obviously a recent development
e. As far as I'm concerned, history stops at my birth
...it probably wasn't first, but it had to be early to have spread into
every
known form of life...
2. Which best describes germination?
___A___
a. Seed sprouting
b. Flower development
c. Sperm meets egg
d. Bending toward light
e. Someone sneezing on you
...right out of the book / notes...
3. Plants probably would not have been able to move onto land without
their
___B___
a. Pollinators
b. Fungus symbionts
c. Root systems
d. Guard cells
e. Credit cards
...also from the book / notes...
4. In genetics and function, pollen is most like
___A___
a. Sperm
b. Seeds
c. Spores
d. Cones
e. Whatever else makes you sneeze
...it has just one set of chromosomes and is getting to the egg cells;
its packaging is just a bit different...
5. Which is a bryophyte?
___C___
a. Rose
b. Fern
c. Moss
d. Pine
e. What language is this?
...right out of the book / notes...
6. The primary purpose of a fruit is to
a. Feed animals
b. Form flowers
___D___
c. Attract attention
d. Move seeds
e. Be thrown in old movies and bad sit-coms
...just remember that it's not what you probably thought it was before
this course...
7. The world's first autotrophs and heterotrophs should have been
___C___
a. All eukaryotes
b. Eukaryotes and prokaryotes
c. All prokaryotes
d. Neither eukaryotes or prokaryotes
e. Pretty rich if they had invested wisely
...both abilities should have evolved before eukaryotes appeared,
since both are found in prokaryotes...
8. As plants evolved, which became the main body form?
___A___
a. Sporophyte
b. Flower
c. Fruit
d. Gametophyte
e. Plants have bodies -?
...right out of the book / notes...
9. In conifers, compared to female cones, male cones are
___D___
a. Higher & larger
b. Lower & larger
c. Lower & smaller
d. Higher & smaller
e. Dumber & smellier
...right out of the book / notes...
10. Another use plants may produce pollen for:
___A___
a. Animal food
b. Seed carrier
c. Directly grow into plants
d. Make people allergic
e. They're really bored
...they have to make lots of extra, but they become a food bribe for
pollinators...
11. The beginnings of mitochondria and chloroplasts are found in the
___B___
a. Colonialism hypothesis
b. Endosymbiont theory
c. Cambrian explosion
d. Gaia hypothesis
e. Unpronounceable names handbook
...out of the book / notes...
12. The Cambrian Explosion seems to have been the beginnings of the
major
___B___
a. Groups of advanced organisms
b. Animal groups
c. Land groups
d. Plant groups
e. Action movies
...out of the notes and handout...
13. The structure of parts inside a flower can be used to determine
___B___
a. Whether the supporting plant is male or female
b. What sort of pollinator it uses
c. If the plant is a seedless or seed plant
d. All of these
e. Whether someone loves you or not
...they're built to get pollen out (however it's done) and then get
pollen
to the female parts of another flower...
14. A fern spore would have the same number of chromosomes as what
from the
same species of fern?
___C___
a. Leaf cell
b. Cone
c. Sperm cell
d. Pollen grain
e. What is this, fern accounting-?
...B and D aren't found in ferns; both spores and
sperm are haploid...
15. In angiosperms, where do pollen tubes first form?
___A___
a. Stigma
b. Anther
c. Seeds
d. Ovaries
e. Are they like Pixie Stix?
...they are built by pollen on the top of the female parts, well above
D and way before C form...
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 are two sets of differences to tell these apart:
| SPERM |
EGG CELLS |
| Much smaller |
Much larger (contains yolk) |
| Many more made |
Way fewer made |
| Have to make way to egg cell |
Must wait for sperm to reach it |
2. What are two of the major full-time land groups of organisms?
...could be plants, insects, arachnids, amphibians, reptiles, birds,
mammals...
3. What is the function of an endosperm?
...it's a food source for a plant embryo...
4. Briefly, what is the main idea of the Gaia hypothesis?
...Earth's environment is stabilized by the Life on it...
5. According to theory, when the Earth's "living things" were just big organic molecules,
what are two features those molecules had to have to lead on to current forms of life?
...they had to be able to reproduce themselves and to evolve...
6. What does haploid mean?
...having only one set of chromosomes...
7. Give two environmental conditions that favor conifers over angiosperms.
...dryer (up to a point), colder, poorer in nutrients...
8. How is a eukaryotic cell different from a prokaryotic cell (one way is all that you
need).
...eukaryotic
cells have nuclei (prokaryotes don't); they also have a lot of
membrane-based inner parts (including mitochondria and chloroplasts) and
multiple chromosomes, which prokaryotes don't...
9. Give two distinctly different ways for pollen to spread.
...it
can spread through wind, through water (rarely), or attached to
pollinators...
10. What is it particularly about pollen that made it such a great development in the
evolution of land plants?
...being able to spread sperm through the air (not needing
"open" water for it) allowed plants to spread across almost
all of the land areas...
11. What are two aspects of a fresh water environment that would have made it an
excellent staging area for the movement of organisms onto the land?
...larger organisms develop waterproofing to keep from being flooded
(water would diffuse into them); shallow systems could require
more leg-like structures; temperatures would fluctuate more;
it might have been necessary to move between pools as they dried
up; there's more sunlight exposure so close to the surface...
12. The evolutionary development of which process led to the formation of the
atmosphere's ozone layer?
...photosynthesis
produces oxygen, which becomes ozone in the upper atmosphere...
13. Define what is meant by a pioneer organism.
...a
species that can move into a "new" environment and survive
there...
14. What exactly is alternation of generations?
...a
life cycle that always includes an asexual phase and a sexual phase...
15. Explain the importance of a cell membrane to the evolution of protocells.
...it
would allow them to "confine" and isolate much of their
chemistry from possible competitors...
16. What are two different types of catastrophes that may have led to mass extinctions?
...Asteroid/comet impacts, volcanic eruptions, maybe ice ages
(catastrophes have to happen fast - some of the other possibilities are
too slow to be considered catastrophes...)
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. Name the four plant tissue types and, for each, give one major function done by that
tissue.
| Dermal Tissue |
Protective coverings, waterproofing, increasing
root absorption area, controlling transpiration |
| Ground Tissue |
Photosynthesis, support, food storage |
| Vascular Tissue |
Moving materials from absorption / production
sites to where they're needed |
| Meristem Tissue |
Growth from new cell production, repair |
2. 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.
| They had to resist drying out in
the air |
| They had to be able to hold
themselves up without water's support |
| They had to resist the way
temperatures can fluctuate in air |
| They had to deal with more direct
sunlight |
| They had to deal with much more
oxygen |
| They had to find ways of
reproducing without support water for sperm |
3. Name and briefly describe four types of vegetative propagation (natural or artificial).
| Rhizomes |
Underground, sprouting stems |
| Runners |
Above-ground, sprouting stems |
| Root sprouting |
New shoots from roots |
| Tubers |
Sprouts from storage structures |
| Leaves |
Some leaves produce new plants |
| Cuttings |
Used to grow new plants from pieces |
| Cultures |
New plants from single starting cells |
4. Describe, with the proper terms, the full life cycle of a fern.
...(diploid) sporophytes produce and release (haploid) spores, which
settle in proper area and sprout to form either male or female
gametophyte; if ground is wet enough, male releases (haploid)
sperm to swim to female (haploid) egg cell for fertilization;
(diploid) zygote grows into new sporophyte...
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. What are four plant functions that are affected strongly by plant hormones?
| Growth |
| Sprouting |
| Orientation (toward light, roots
down, shoots up) |
| Maturity |
| Defense against plant-eaters |
| Damage response |
| Ripening of fruit |
NO 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.
Where on earth can you find, for Three Points Each:
Fossil
stromatolites?
Living stromatolites?
The Burgess Shale fossils contain many animal types that no longer exist. What's the most
likely reason for their disappearance? Four Points.
According to the latest scientific theory, what animals may be actual surviving dinosaurs?
Three Points.
Why is disease most probably not a cause of mass extinctions? Four Points.
How do you tell a real fern from a fern-like flowering plant? Four Points.
What does "-phyte" mean? Three Points.
Many primitive plants have a non-reproductive reason for needing to be in moist
environments. What is it? Four Points.
Why does stripping the bark off most trees eventually kill them?
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