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35 Minutes—40 Questions
Passage I
According to the chemical equation, hydrogen peroxide (H2O2) breaks down in the presence of
the enzyme catalase to produce water (H2O) and oxygen gas (O2).
2H2O2  2H2O + O2
To examine this decomposition, students conducted 2 experiments. Steps 1 through 3 were
carried out in every trial of the experiments:
1. An aqueous catalase solution maintained at a certain pH was applied for 2 minutes to a fresh, circular
piece of filter paper with a diameter of 6.0 mm.
2. The solution was drained of the filter paper. The filter paper was then swiftly pushed to the bottom of
a beaker containing 500 mL of freshly made aqueous solution with a specific concentration of H2O2 using
a glass rod (see Figure 1).
3. The glass rod was removed as soon as the filter paper touched the bottom of the beaker, and the
reaction's gas bubbles encircled it, leading it to rise to the top of the liquid. The amount of time needed
for the filter paper to rise to the surface was measured as the rising time, or RT.
Experiment 1
The catalase solution was kept at a pH of 6, and Trials 1–5 examined H2O2 solutions with varying
concentrations (percent H2O2 by volume). The outcomes are displayed in Table 1.
Experiment 2
Trials 1 through 5 were repeated three times, with the exception that each set of trials tested a different
pH. Table 2 presents the outcomes.
1. Which of the following combinations of pH
and H2O2 concentration resulted in the
shortest RT in Experiment 2?
A. 5
B. 5
C. 7
D. 7
2. In Experiment 2, the following numbers of
circular pieces of filter paper were used:
F. 05.
G. 10.
H. 15.
J. 20.
3. Assume that another experiment was
conducted in Experiment 1 and that its RT was 8
seconds. Which of the following best describes
the H2O2 concentration for this experiment?
A. 0.4%
B. 0.7%
C. 1.6%
D. 2.2%
C. O2
D. H2O2
4. Which trial, Trial 2 or Trial 7, saw a faster
breakdown of H2O2?
F. Trial 2; the faster breakdown was correlated
with a shorter RT.
G. Trial 2; the faster breakdown was correlated
with a longer RT.
H. Trial 7; the faster breakdown was correlated
with a shorter RT.
J. Trial 7; the faster breakdown was correlated
with a longer RT.
6. Assume that the H2O2 solution volume in the
beaker during Step 2 had been 400 mL in each
trial of Experiment 1. Which of the following
describes the RT in Trial 5 as being most likely?
F. 08 sec
G. 10 sec
H. 14 sec
J. 16 sec
5. Take into account the gas bubbles that led to
the filter paper rising to the surface. Which of
the following chemicals most likely made up the
majority of the interior of these gas bubbles?
A. H2O
B. Catalase
7. What was the range of RT values for the trials
carried out at a neutral pH, as determined by
the outcomes of Experiments 1 and 2?
A. 07 sec−19 sec
B. 08 sec−22 sec
C. 10 sec−27 sec
D. 18 sec−50 sec
Passage II
The environment in which bacteria are produced has an impact on how many of them stick to a
surface. Two investigations compared the quantity of bacteria, such as Escherichia coli or Salmonella
typhimurium that attach to stainless steel surfaces using various mediums.
Study 1
Steps 1 through 8 were carried out in each of the 4 trials:
1. A flask contained five 0.36 cm2 stainless steel chips.
2. The flask was filled with 125 mL of 10% soy broth (in water).
3. The flask was filled with a 15 mL sample of an E. coli culture with a cell density of 100,000 cells/mL.
4. The flask was incubated for 1hr, 24hr, 48hr, or 72hr at 23°C.
5. After being taken out of the flask, the chips were cleaned using Ringer's solution (an aqueous salt
6. The chips were dipped into a euchrysine solution (a dye that stains DNA).
7. Pure water was used to wash the chips.
8. To calculate the average number of cells per cm2 of chip, the number of E. coli adhering to each chip
was counted.
Repeating steps 1 through 8, 4 trials were run with each of the following 3 media: 100% soy broth, skim
milk, and 20% meat juice (in water).
Study 2
Study 1 was replicated, however this time S. typhimurium was used in place of E. coli (see Table 2).
8. It is expected that the average number of E.
coli cells/cm2 in 10% soy broth would have been
as follows in Study 1 if an incubation duration of
36 hours had been used:
F. less than 2,300 cells/cm2
G. between 2,300 call/cm2 and 12,000 cells/cm2
H. between 12,000 call/cm2 and 49,000
cells/cm2 centimeter
J. more than 49,000 cells/cm2 centimeter
9. Assume a student wants to grow E. coli in a
medium that will reduce, as much as feasible,
the bacteria's adhesion to a stainless steel
surface throughout the course of a 72-hour
incubation period. Which of the 4 media
evaluated should the student choose, according
to the findings of Study 1?
A. 10% soy broth
B. 100% soy broth
C. Skim milk
D. 20% meat juice
10. What function did the euchrysine solution
serve in each study's trial?
F. To enable visualizing the cells that were
affixed to each chip.
G. Before staining the cells, remove any cells
that were just tangentially connected to each
H. To give the cells a supply of nutrition
J. After staining the cells, remove any excess
dye from the chips.
11. Which of the tested medium had an average
S. typhimurium cell density that was higher than
the average E. coli cell density for all four of the
incubation durations examined, according to
the findings of Studies 1 and 2?
A. 10% soy broth and 100% soy broth only
B. 10% soy broth and skim milk only
C. 100% soy broth and 20% meat juice only
D. Skim milk and 20% meat juice only
12. Any extra dye that remained on the
stainless steel chip after the cells attached to it
were stained had to be cleaned off before the
cells could be examined. Which procedure was
most likely used in the research to complete
this task?
F. Step 4
G. Step 5
H. Step 6
J. Step 7
13. Which of the following claims regarding the
quantity of S. typhimurium that cling to a
stainless steel surface in response to either 10%
soy broth or skim milk is consistent with Study
2's findings? As the incubation period for S.
typhimurium extends from 1 hour to 72 hours
A. 10% soy broth causes an increase in average
S. typhimurium cells/cm2 before being constant.
B. 10% soy broth, the average S. typhimurium
cell/cm2 initially drops and then stabilizes.
C. skim milk, the average S. typhimurium
cell/cm2 centimeter only rises.
D. skim milk, the typical density of S.
typhimurium cells/cm2 only falls.
14. What kind of subunit was the
macromolecule in the research that coloured
the cells made up of?
F. Amino acid
G. Fatty acid
H. Monosaccharide
J. Nucleotide
Passage III
The amount of phosphorus (P) in forest soil can be impacted by the presence of earthworms.
Two nearby oak woodlands, Forest W (an old forest) and Forest Z (a young forest), were used for the
studies. The soil type in both forests was the same.
In each forest, two 100 m2 plots were chosen: one that had been overrun by earthworms
several years before to the start of the experiments, and one that had none (see Table 1).
Study 1
Each plot has three holes bored into it. A 10 cm3 volume of soil was taken from the hole's wall in each
hole, as well as at depths of 3 cm, 6 cm, 9 cm, and 12 cm. Particles greater than 2 mm in diameter were
eliminated from the single sample made up of all the soil volumes collected from the holes in a plot. The
total soil P content, measured in mg P/cm3, was determined after oven drying each plot's sample (see
Figure 1).
Study 2
Samples of the soil solution (the aqueous solution that exists between soil particles) were taken from
each plot using a pair of lysimeters that had been set up two years prior to the start of the
investigations. In one lysimeter, a sample of soil solution was taken from a depth of 12 cm (shallow), and
in the other, a sample was taken from a depth of 36 cm (deep). The amount of soluble reactive P (SRP;
one of several types of P found in soil solution), measured in micrograms of P per liter (μg P/L), was
detected for each sample (see Figure 2).
15. Why were the soil samples from Study 1
oven dried before being analyzed?
A. To increase the soil mass
B. To increase the water content
C. To remove most or all SRP
D. To remove most or all water
16. Which of the following claims best explains
why the lysimeters were set up two years
before the study got underway? The two years
provided time for the following:
F. holes that must be drilled in the plots
G. the disturbed soil to settle once more
H. The concentration of SRP will drop to zero
J. oak trees must reach a specific minimum
17. Which of the following assertions best
explains why only the top 12 cm of soil was
taken into account in Study 1?
A. The highest depth of the soil was less than 12
B. The soil was deeper than 12 cm at its deepest
C. Only at depths of less than 12 cm did the
earthworms exist.
D. Only depths deeper than 12 cm supported
the earthworms' existence.
18. To ascertain the impact of a forest's age on
total soil P in the absence of earthworms, which
two plots should be compared?
F. Plots 1 and 2
G. Plots 1 and 3
H. Plots 2 and 4
J. Plots 3 and 4
19. In Study 1, every component of the samples
that were examined for total soil P was:
A. a diameter of less than or equal to 2 mm
B. having a diameter of between 2 and 3 mm
C. having a 3 mm diameter
D. having a diameter more than 3 mm
20. What was the maximum depth at which soil
samples from Study 1 were collected? 20. What
was the highest depth at which soil solution
samples from Study 2 were collected?
H. 2
J. 3
21. Take into account Forest W's Study 2
findings. Was the SRP concentration in the plot
with earthworms higher or lower than the SRP
concentration in the plot without earthworms
for each of the two depths?
Passage IV
The sensory neurons in the antennae of the moth Manduca sexta can vary their electrical
activity in response to certain odorants (airborne chemical compounds). An increase in the antenna's
voltage in comparison to its voltage in the absence of odorants can be used to detect a change in an
antenna's electrical activity. For adult female M. sexta exposed to each of the 5 odorants at each of the
4 concentrations, the average change in antennal voltage is shown in the figure below.
22. The average change in antennal voltage as
the odorant concentration rose from 1 mg/L to
100 mg/L was as follows:
F. decreased only for all 5 odorants.
G. increased only for all 5 odorants.
H. lowered just 4 odorants, however she
decreased 1 odorant before increasing it.
J. only raised 4 odorants, however she added 1
odorant before decreasing it.
23. According to the figure, the average change
in antennal voltage for adult female M. sexta
exposed to 5 mg/L of methyl salicylate will most
likely be: A. less than 60 V.
A. less than 60 μV
B. between 60 μV and 120 μV
C. between 120 μV and 185 μV
D. greater than 185 μV
24. Which of the following odorant and
concentration combinations had an average
change in antennal voltage that was most
similar to the average change in antennal
voltage for nerolidol at 50 mg/L?
propylacetone 1 mg/L
10 mg/L
caryophyllic acid
50 mg/L
methyl salicylate
100 mg/L
25. From the odorant that stimulated the least
average change in antennal voltage to the
odorant that stimulated the largest average
change in antennal voltage, what is the order of
the 5 odorants for the M. sexta subjected to a 1
mg/L odorant concentration?
A. Caryophyllic acid, linalool, methyl salicylate,
nerolidol, propylacetone
B. Caryophyllic acid, methyl salicylate, nerolidol,
linalool, propylacetone
C. Propylacetone, methyl salicylate, nerolidol,
caryophyllic acid, linalool
D. Propylacetone, nerolidol, caryophyllic acid,
methyl salicylate, linalool
26. The sentence claims that specific chemical
substances have the ability to induce a change
in the electrical activity of a particular type of
neuron in M. sexta. What body part organ
contains this kind of neuron?
F. Liver
G. Ears
H. Heart
J. Nose
27. Would it be more accurate to say that the
neurons mentioned in the passage are part of
the peripheral nervous system or the central
nervous system?
A. Central; this group of neurons is responsible
for receiving and processing information from
other neurons.
B. Central; these neurons' function is to take in
environmental cues and then transmit that
information to other neurons.
C. Peripheral; these neurons' function is to
gather and analyze data from other neurons.
D. Peripheral; these neurons' function is to take
in environmental cues and then transmit that
information to other neurons.
Passage V
The central body (moon or planet) that the satellite orbits, the orbital height, and the mass of
the spacecraft all affect the orbital energy of the satellite. For each of the 12 separate satellites, these
properties are listed in Table 1.
The amount of time needed for a satellite to make one rotation around its primary body is
known as its orbital period. A satellite's orbital time is depicted in Figure 1 as a function of altitude
above the Moon, Mars, and Earth.
28. Take into account a satellite that orbits
Mars once in exactly five hours. Which of the
following best describes the altitude at which
this spacecraft orbits, according to Figure 1?
F. 3,200 km
G. 3,600 km
H. 4,000 km
J. 4,400 km
29. Take into consideration the statement, "For
a given central body and a certain satellite
mass, the greater the orbital energy." Which
subset of the satellites listed in Table 1 could be
used as proof for this claim?
A. Satellites 1−4 only
B. Satellites 5−8 only
C. Satellites 1−4 and Satellites 9−12 only
D. Satellites 5−8 and Satellites 9−12 only
30. Picture three satellites, one each orbiting
the Moon, Earth, and Mars. Each satellite orbits
above its core body at the same height and has
the same mass. Whose satellite orbiting which
central body most likely completes a revolution
in the shortest amount of time, according to
Figure 1?
F. Moon
G. Earth
H. Mars
J. Cannot be determined from the given
31. Take a look at the satellites 5–8 data. Which
extra satellite should be grouped with Satellites
5–8 in order to better illustrate the trend in this
data set?
A. Satellite 2
B. Satellite 3
C. Satellite 9
D. Satellite 10
32. The diagram below (which is not drawn to
scale) displays the satellite's height, center-tocenter distance (d), and radius, R, for a central
Which satellite's d would be higher, according
to the information about Satellites 2 and 10 in
Table 1?
F. Satellite 2, because its altitude is higher than
that of Satellite 10's.
G. Satellite 2, as the Moon's R is higher than the
Earth's R.
H. Satellite 10, as its height is higher than that
of Satellite 2, which is at a lower altitude.
J. Satellite 10, as Earth's R is higher than the
Moon's R.
33. Which of the following questions cannot be
addressed without more information than what
is provided in Table 1 and Figure 1?
A. What is the orbital energy of a 100 kilogram
satellite in a 400 km orbit around Mars?
B. If a 100 kg spacecraft has an orbital energy of
3,984 MJ, at what altitude does it orbit the
C. A satellite in orbit around Mars at an altitude
of 400 km makes about how many rotations per
D. At a 400 km altitude, how long does it take a
satellite to make one round around the Earth?
Passage VI
A model of acids and bases was offered by each of the three experts.
Scientist 1
When dissolved in H2O, an uncharged material called an acid dissociates (splits into two or more
ions), releasing 1 or more hydrogen ions (H+) and a matching negative ion. When dissolved in H2O, a
base is an uncharged material that breaks down into a metal ion and 1 or more hydroxide ions (OH-).
Hydrochloric acid (HCl), which splits into H+ and a chloride ion (Cl-) in H2O, is an example of an acid.
Sodium hydroxide (NaOH), which splits into sodium ion (Na+) and OH- in H2O, is an example of a base.
Scientist 2
In a chemical reaction, an acid is a charged or uncharged substance that gives an H+ to a base to
form a covalent bond. In a chemical process, a base is an uncharged or charged material that receives an
H+ from an acid-containing molecule and creates a covalent bond.
Because it gives the H2O an H+ in its reaction with HCl, HCl is an acid. The hydronium ion (H3O+)
and Cl- are created when the donor H+ and H2O establish a covalent bond. H2O acts as a base in this
reaction because it accepts the H+ from HCl.
Scientist 3
In a chemical process, an acid is a neutral or charged material that absorbs a pair of electrons
from a base, which is a neutral or charged substance that contributes the pair of electrons. Between the
atom in the base that is donating the electrons and the atom in the acid that is accepting them, a new
covalent bond is formed as the electrons are transferred. A current acid bond is also broken at the same
Because it accepts a pair of electrons from H2O during the reaction between HCl and H2O, HCl
acts as an acid. The H atom in HCl forms a covalent link with the O atom in H2O at the same moment
that the bond between the H atom and the Cl atom in HCl is broken. The results are H3O+ and Cl-. H2O
acts as a base in this reaction by giving the H atom of the HCl molecule a pair of electrons.
34. Which of the following assertions
concerning H2O or HCl were made by all
3 scientists?
F. H2O is an acid.
G. H2O is a base.
H. HCl is an acid.
J. HCl is a base.
35. Which of the following ways does Scientist
2's description of an acid differ from Scientist
3's? Scientist 2 claims that an acid:
A. receives two electrons, whereas an acid, in
accordance with Scientist 3, provides an H+.
B. gives away two electrons, whereas an acid,
according to Scientist 3, takes an H+.
C. whereas an acid, according to Scientist 3,
offers a pair of electrons, takes an H+.
D. gives an H+ whereas an acid, in accordance
with Scientist 3, takes two electrons in.
36. Take into account the claim that all bases
contain hydroxide ions. Which scientist is most
likely to concur with the claim?
F. Scientist 1 only
G. Scientist 3 only
H. Scientists 1 and 2 only
J. Scientists 2 and 3 only
37. Take into consideration the adage "In any
chemical reaction, there must also be a material
that serves as a base." Which scientist, if any,
from numbers two and three, would be most
likely to concur with this assertion?
A. Scientist 2 only
B. Scientist 3 only
C. Both Scientist 2 and Scientist 3
D. Neither Scientist 2 nor Scientist 3
38. Hypochlorous acid's chemical name is HOCl.
HOCl dissociates into the following compounds
in H2O, supporting Scientist 1's claim that it is an
F. H− and ClO+ .
G. H+ and ClO− .
H. OH− and Cl + .
J. OH+ and Cl − .
39. Which of these can never serve as a base in
a reaction, according to Scientist 3's model: a
single H or single O atom? An element of:
A. H., as it has less than 2 electrons.
B. H. due to the presence of more than
2 electrons.
C. O., as it has less than 2 electrons.
D. O. as it contains more than 2 electrons.
40. Take the model proposed by Scientist 2. The
portion of an acid that is still present after the
acid has given the H+ in a reaction is known as
the conjugate base of the acid. What chemical
serves as the conjugate base in the reaction
that Scientist 2 described?
F. H2O
G. H3O+
H. HCl
J. Cl −