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Set 2
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DIRECTIONS: The passages in this test are followed by several
questions. After reading each passage, choose the best answer to each
question and fill in the corresponding oval on your answer document.
You may refer to the passages as often as necessary.
You are NOT permitted to use a calculator on this test. | |
Passage I
The following table represents the
concentration of ions and dissolved gases in the sediment at the bottom
of an ocean. A depth of 0 centimeters (cm) represents the top of the
sediment. The concentrations are expressed in parts per million (ppm).
The acidity of a solution is represented on a scale known as pH. A pH of 1 is very acidic, a pH of 7 is neutral, and a pH of 14 is very basic.
|
Depth
(cm) | Temperature
(oC) | pH | Concentration in sediment (ppm) |
| SO42- | S2- | CO2 | Fe3+ | Fe2+ | O2 |
| 0 | 4 | 7.0 | 7.0 | 0.0 | 1.0 | 4.0 | 0.5 | 2.0 |
| 5 | 5 | 6.5 | 5.0 | 2.0 | 1.5 | 3.0 | 1.5 | 1.0 |
| 10 | 7 | 6.0 | 3.5 | 3.5 | 2.0 | 2.0 | 2.0 | 0.0 |
| 15 | 9 | 5.5 | 3.3 | 3.8 | 3.0 | 0.8 | 3.8 | 0.0 |
| 20 | 10 | 5.0 | 3.0 | 4.0 | 1.0 | 0.5 | 4.0 | 0.0
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Table adapted from R.M. Atlas and R. Bartha, Microbial Ecology: Fundamentals and Applications.
©1981 by Addison-Wesley Publishing Company. |
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1. | According to the
information provided in the table, the concentration of which of the
following ions and dissolved gases is constant for sediment depths of
10 cm or more? A. Sulfide (S2-)
B. Carbon dioxide (CO2)
C. Ferric iron (Fe3+)
D. Oxygen (O2) |
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2. | The graph below best
represents the relationship between concentration and sediment depth
for which of the following ions and dissolved gases?
F. Ferrous iron (Fe2+)
G. Oxygen (O2)
H. Carbon dioxide (CO2)
J. Sulfate (SO42-) |
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3. | If the trends indicated in the table were to continue, one would predict the pH of the sediments at a depth of 35 cm to be: A. 1.5.
B. 3.5.
C. 4.5.
D. 6.0. |
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4. | A certain type of bottom-dwelling microorganism thrives under the following environmental conditions: low concentrations of Fe2+, high concentrations of O2, and a neutral pH. Based on the table, at which of the following sediment depths would one most likely find this microorganism? F. 0 cm
G. 5 cm
H. 10 cm
J. 15 cm |
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5. | A researcher wants to
determine whether an unidentified sediment sample was drawn from a
depth of 15 cm or 20 cm. Based on the information in the
table, which of the following would NOT confirm the depth of the sample? A. O2 concentration
B. Fe3+ concentration
C. S2- concentration
D. pH |
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Passage II
The Sun's path from sunrise to sunset varies
with the time of year. A student performed the following experiments on
three clear, sunny days at three- or four-month intervals throughout
the course of a year to study the path of the Sun through the sky.
Experiment 1 At a chosen Northern
Hemisphere location, the student placed a stick vertically into the
ground so that 1 meter of its length was left above ground. The student
knew that the length of the shadow was related to the height of the Sun
above the horizon and that the shadow would point away
from the direction of the Sun. The length in meters (m) and direction
of the shadow cast by the stick were measured one hour after sunrise
(Shadow A), at mid-morning (B), at noon (C), at mid-afternoon (D), and
one hour before sunset (E) on each of the three days. The direction of
each shadow was determined by placing a magnetic compass at the base of
the stick and aligning the north arrow with the north mark on the
compass. The direction of each shadow was then determined by a
comparison with the compass face markings. The results are recorded in
Table 1. |
| Table 1 |
| Shadow | Day 1 | Day 2 | Day 3 |
Length
(m) | Shadow
direction | Length
(m) | Shadow
direction | Length
(m) | Shadow
direction |
| A | 5.0 | SW | 8.6 | NW | 6.8 | W |
| B | 1.2 | W | 2.9 | NNW | 1.7 | NW |
| C | 0.3 | N | 2.3 | N | 0.9 | N |
| D | 1.2 | E | 3.0 | NNE | 1.8 | NE |
| E | 5.0 | SE | 8.6 | NE | 6.9 | E
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| Experiment 2
The following year, the student repeated
Experiment 1 at a chosen location in the Southern Hemisphere. The
results are in Table 2. |
| Table 2 |
| Shadow | Day 1 | Day 2 | Day 3 |
Length
(m) | Shadow
direction | Length
(m) | Shadow
direction | Length
(m) | Shadow
direction |
| A | 9.0 | SW | 5.0 | NW | 6.9 | W |
| B | 3.2 | SSW | 1.1 | W | 1.8 | SW |
| C | 2.5 | S | 0.3 | S | 1.0 | S |
| D | 3.2 | SSE | 1.1 | E | 1.8 | SE |
| E | 9.1 | SE | 5.0 | NE | 6.9 | E
|
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6. | Which of the following was a constant in both experiments? F. Length of vertical stick exposed
G. Shadow direction
H. Day of the year
J. Shadow length |
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7. | If the experiments
were repeated after pounding the stick farther into the ground so that
only 0.5 m was exposed, how would this affect the shadow lengths? A. They would be twice as long as those in the original experiments.
B. They would be one-and-one-half times as long as those in the original experiments.
C. They would be one-half as long as those in the original experiments.
D. They would be one-fourth as long as those in the original experiments. |
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9. | When the Sun is at an altitude 45o
above the horizon, a vertical object will cast a shadow with a length
equal to the object's height. Which of the following days included a
measurement taken when the Sun was at an altitude of 45o ? A. Day 1 in Experiment 1
B. Day 1 in Experiment 2
C. Day 2 in Experiment 1
D. Day 3 in Experiment 2 |
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10. | Which of the following statements is best supported by the direction of Shadow A on each of the three days in Experiment 1 ? F. The direction of sunrise along the horizon varies throughout the year.
G. Shadows never point due south in the Northern Hemisphere.
H. Shadows never point due north in the Northern Hemisphere.
J. The Sun's brightness varies throughout the year. |
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11. | Based on the
shadow directions in these experiments, which of the following best
describes the difference between the apparent path of the Sun as seen
from the observation points in the Northern and Southern Hemispheres? A. The Sun travels a more southerly path in the Southern Hemisphere than in the Northern Hemisphere.
B. The Sun travels a more northerly path in the Southern Hemisphere than in the Northern Hemisphere.
C. The Sun rises in the East and sets in the West in the Northern Hemisphere, but the opposite is true in the Southern Hemisphere.
D. The Sun rises in the West and sets in the East in the Northern Hemisphere, but the opposite is true in the Southern Hemisphere. |
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