ACT SAMPLE SCIENCE TEST 14
DIRECTIONS: This test consists of seven passages, each followed by several questions. Read each passage
and select the best answer for each question following the passage. Then, on your answer sheet, mark the
oval corresponding to the best answer. You may NOT use a calculator on this test.
Passage I
A virus is a tiny particle that needs a multicellular host, such as a plant or animal, in which to live
and replicate. Unlike bacteria, viruses cannot live and reproduce without a host. Viruses wait in the
environment and can enter a host through the nose, the mouth, or a cut in the skin. Once successfully
inside of an organism, the virus finds a host cell to invade, causing infection and disease.
The average time that elapses between exposure to a virus and the appearance of symptoms is
called the incubation period. The period of time during which a person with a viral infection is capable
of passing the virus onto others is called the contagious period.
Table 1 shows the incubation period and the contagious period for several skin infections caused
by viruses. All of the viruses in Table 1 attack host cells that line the skin.
Table 1
Contagious Period Begins
Contagious Period Ends
Chicken pox
Incubation
Period
11-23 days
4 days after symptoms appear
when all sores have scabbed over
Roseola
8-10 days
onset of fever
when rash is gone
Measles
9-13 days
5 days before rash appears
7 days after rash is gone
Erythema Infectiosum
5-14 days
7 days before rash appears
when rash appears
Hand, Foot, and Mouth
Disease
2-6 days
onset of sores in mouth
when fever is gone
Infection
Table 2 shows the incubation period and the contagious period for several respiratory infections caused
by viruses. All of the viruses in Table 2 attack host cells that line the respiratory tract.
Infection
Bronchiollils
Incubation Period
3-7 days
Table 2
Contagious Period Begins
onset of cough
Common Cold
1-3 days
onset of symptoms
1 day after fever is gone
Influenza
1-2 days
onset of symptoms
1 day after fever is gone
Viral Sore Throat
3-6 days
onset of symptoms
when fever is gone
Croup
1-5 days
onset of cough
when fever is gone
Contagious Period Ends
7 days after onset of cough
1) Roseola is an infant skin disease that is characterized by a high fever for 3-5 days and a red rash
(appearing once the fever has subsided) that lasts for approximately 48 hours. According to
Table 1, the virus that causes Roseola is contagious for :
A) 1-3 days.
B) 2-5 days.
C) 5-7 days.
D) 8-10 days.
2) Based on Table 1, which of the following is the most common symptom of skin disease?
F) Measles
G) Mouth sores
H) Fever
J) Rash
3) According to Table 1 and Table 2, the viral infection that takes the least amount of time to
produce any symptoms is:
A) chicken pox.
B) croup.
C) influenza.
D) viral sore throat.
4) Which of the following would most likely reduce the contagious period of the virus that causes
chicken pox?
F) A cream that dries out the sores.
G) Pain relievers that quickly lower high fevers.
H) Medicine that lessens the cough.
J) An ointment that moistens the sores.
5) The HIV virus causes a progressive infection that damages the immune system. Which of the
following is most likely true of the HIV virus?
A) The HIV virus has one of the shortest contagious periods of any known virus.
B) The HIV virus attacks the cells of the immune system.
C) The incubation period of the HIV virus is similar to those of respiratory viruses.
D) The incubation period of the HIV virus is shorter than most.
Passage II
Mosquitoes are small flying insects that can be found in almost every corner of the planet.
These insects not only are annoying but are also capable of carrying harmful viruses that can be passed
on to humans and animals. Several scientists attempt to determine which environmental factors
contribute to the high number of mosquitoes in a particular area and the species of mosquitoes that
pose a threat to the people in that area. The numbers of mosquitoes was measured using a process
called “mosquito trapping.” Female mosquitoes were collected with various light traps on each of 6
days, beginning at 6:00 p.m. for exactly 1 hour. Light traps emit carbon dioxide, heat, and moisture,
which attract biting mosquitoes, while simultaneously vacuuming the insects into a collection net.
Female mosquitoes (as opposed to male) were collected because the female seeks blood to obtain the
proteins necessary for the development of her eggs.
Study 1
One group of scientists believes that female mosquitoes lay eggs in areas that experience a lot
of rain, because mosquitoes typically lay their eggs in temporary standing water sources (areas that
have collected rainwater). The first two stages of mosquito egg development (the larva and pupa
stages) also occur in water. Table 1 shows the various collection sites and the average number of adult
mosquitoes collected at each site per day.
Collection Site
City Street
Park
Bog
Forest
Pond
Swamp
Roadside Ditch
Table 1
Avg. Number Collected (2002)
219
378
572
1,013
2,170
3,800
4,110
Avg. Number Collected (2003)
690
557
610
1,207
2,912
3,960
7,098
Study 2
Another group of scientists suspects that the population of mosquitoes is also affected by
predator species in the environment. Four different predators in the area studied feed on mosquitoes:
bats, purple martins, whippoorwills, and poorwills. Table 2 shows the approximate number of adult
mosquitoes collected per day in 4 similar but separate areas where each of the predator species is most
prevalent.
Location
A
B
C
D
Predator Species
Bats
Purple Martins
Whippoorwills
Poorwills
Table 2
Avg. Number Collected (2002)
1,264
899
410
685
Avg. Number Collected (2003)
1,329
1,100
303
597
Study 3
A third group of scientists collected and analyzed different species of mosquitoes in a wooded
area to determine the larval habitat, presence of harmful viruses, and the nuisance level to humans.
The nuisance level is based on how frequently the mosquitoes in that area bite and bother humans and
animals. The results of the study are shown in Table 3. The wooded area is most similar to a forest.
Table 3
Species
Larval Habitat
Virus*
1
Bog
EEE
2
Ditch
None
3
Forest
SLE
4
Pasture
None
5
Swamp
EEE
*Note: EEE = Eastern Equine Encephalitis, SLE = Saint Louis Encephalitis
Nuisance Level
High
Medium
Medium
High
Low
6) A mosquito control program is typically enforced to keep humans from being bothered or bitten
by mosquitoes. Which of the following activities should be performed next if the scientists in
Study 3 want to determine which area needs to better enforce its mosquito control program?
F) Continue a similar study in a neighboring city.
G) Determine where the species with high nuisance levels are located.
H) Collect and analyze samples of standing water in each of the areas.
J) Study how and when the predator species feed on mosquitoes.
7) If the scientists were able to focus on the elimination of one of the mosquito species in Table 3,
which of the following would they most likely choose?
A) Species 1, because it carries a harmful virus and has a high nuisance level.
B) Species 2, because of the location of the larval habitat.
C) Species 3, because of the harmful SLE virus present.
D) Species 4, because of the high nuisance level.
8) According to Study 1, the scientists’ hypothesized that:
F) standing water sources reduced the number of mosquitoes collected.
G) the increase in virus-carrying mosquitoes was caused by high temperatures.
H) areas with more standing water had higher populations of mosquitoes.
J) forest areas were home to the most mosquito larvae.
9) Based on the results of Studies 1 and 2, all of the following appear to reduce mosquito
populations EXCEPT:
A) reducing the number of standing water sources in an area.
B) the presence of predator species in the area.
C) increasing the number of predator species in an area.
D) reducing the number of whippoorwills and poorwills in an area.
10) Which of the following best explains why only female mosquitoes were collected in the studies?
F) Male mosquitoes are too aggressive and cannot be caught.
G) Female mosquitoes are the easiest to collect and analyze.
H) Only female mosquitoes actually bite because they require a blood meal.
J) The anatomy of a female mosquito is easier to study.
11) According to the results of Study 1, which of the following is most likely true?
A) The roadside ditch had the most standing water available for mosquitoes to lay eggs.
B) There was a decrease in the number of mosquitoes found from 2002 to 2003.
C) The park had the smallest number of mosquitoes found because it had the least standing
water available.
D) The city street had the least mosquitoes because it had the most standing water available.
Passage III
Smog, the yellowish-brown haze that is suspended above many metropolitan areas, is mostly
made up of nitrogen oxides (NOx) and volatile organic compounds (VOC). Ozone (O 3) is also present at
ground level. Smog is created when the 2 pollutants, NOx and VOC, combine and react with sunlight. At
ground level, ozone is very different from the ozone layer of the atmosphere that protects us from the
sun’s rays. Ground-level ozone contributes to the occurrence of human respiratory problems, acid rain,
and global warming. In addition, the pollutants in smog can be carried by the wind to other locations
that are not the source of the pollution.
Burning fuel at a high temperature produces the pollutant NOx. Many forms of transportation,
such as motor vehicles, ships, trains, and airplanes; many industrial, agriculture, and forestry processes;
and many human activities burn fuel and create NOx. VOC, the other component of smog, is created
from the evaporation of liquid fuels, mainly from various industrial processes, and the emission of
unburned hydrocarbons from automobile exhaust. Industrial processes are mostly responsible for the
burning of coal, which emits both NOx and VOC.
Figure 1 shows the percent contribution from the 4 main sources of NOx and VOC emissions in a
particular region. (Motor vehicles include both gasoline and diesel vehicles.)
Figure 2 shows the percent contribution of NOx and VOC emissions from transportation sources
in a particular region.
Figure 3 shows the percent contribution of NOx and VOC emissions from the burning of
different fuel types in a particular region.
12) According to the passage, if you compared the NOx levels near a busy highway to a remote rural
area with very few gasoline or diesel-fueled vehicles:
F) NOx levels would be higher near the highway than in the rural area.
G) NOx levels would be lower near the highway than in the rural area.
H) NOx levels would be the same in either area.
J) NOx levels are not affected by motor vehicle emissions.
13) According to Figure 3 and information in the passage, which of the following is true of NOx and
VOC emissions?
A) VOC emissions are always greater than NOx emissions.
B) Propane that is burned has no effect on smog or pollution.
C) The burning of furnace oil contributes the least to NOx and VOC emissions.
D) The highest proportion of both pollutants come from industrial processes.
14) Airplanes are another source of NOx and VOC emissions. If airplanes produce about the same
amount of NOx and VOC as trains, you would expect that:
F) airplanes contribute about 4% to NOx emissions.
G) NOx emissions would increase over time.
H) VOC emissions would decrease over time.
J) airplanes contribute about 10% to VOC emissions.
15) According to the passage, which of the following mobile sources contribute the least to the
emission of nitrogen oxides into the atmosphere?
A) Gasoline-fueled vehicles
B) Diesel-fueled vehicles
C) Trains and ships
D) Gasoline-fueled vehicles and trains
16) On certain days, in remote areas far from factories and motor vehicles, heavy smog appears.
Smog in remote areas:
F) cannot occur if no factories or motor vehicles are present.
G) may occur if the area is downwind from a factory or busy highway.
H) may occur more often if the area is a desert region.
J) may occur more often if the area is near a body of water.
17) According to the passage, which of the following would most likely lead to heavy smog on a
particular day?
A) Heavy traffic only
B) Swirling winds and global warming
C) A lot of sunshine and heavy traffic
D) Heavy winds and a lot of rain
Passage IV
The cells of multicellular organisms are constantly communicating: sending, receiving, and
interpreting signals from other cells and the environment in order to compose the appropriate
responses. One normal component of cell health and development is apoptosis, which is an example of
this communication between cells. Apoptosis is a normal and healthy process that regulates the death
of a cell that is unnecessary, unwanted, or damaged. The cell itself responds to a variety of signals that
instruct it to kill itself. During this process, the cell is playing an active role in its own death.
Apoptosis can be induced by either an internal signal or an external signal. Internal signals are
produced when the cell experiences cellular stress, such as exposure to radiation and chemicals, or a
viral infection. External signals are received by cell surface receptors and are transmitted to the
cytoplasm, the fluid on the inside of the cell, which begins to self-destruct. External signals occur when
other cells recognize virus-infected cells nearby and send a message to and stop the spread of a disease
such as cancer. In addition, cells may undergo apoptosis to support development. For example, as a
tadpole naturally develops into a frog, it loses its tail. Apoptosis is responsible for the destruction of the
cells in the tail.
Once a signal has been transmitted to a cell, the cytoplasm begins to shrink, followed by the
breakdown of proteins within the cell, which causes the cell to take on a horseshoe-like shape. The cell
will continue to shrink, forming tiny blisters (denoted by an arrow in Figure 1) that makes it easier for
phagocytic cells to do their job and remove the fragmented cell from the tissues of an organism. This
process is illustrated in Figure 1.
Figure 1
18) According to the passage, which of the following is a likely example of apoptosis in support of
development?
F) Growth of thicker fur on calves after birth
G) Development of cancer in most individuals
H) Formation of tiny hairs on the surface of a human’s skin
J) Disintegration of skin between an unborn child’s fingers and toes
19) Why might apoptosis often be referred to as a cell “committing suicide”?
A) The cell initiates its own death.
B) The cell is damaged and cannot be repaired.
C) All organisms that possess the cells are in pain.
D) All cells that die engage in apoptosis.
20) Based on information in the passage, all of the following are true about apoptosis EXCEPT:
F) apoptosis of a cell may be stimulated by internal or external signs.
G) it is abnormal for a cell to induce its own death through apoptosis.
H) a signal is transmitted into a cell before disintegration occurs.
J) apoptosis may occur during the natural development of an organism.
21) According to Figure 1 and information in the passage, a cell that is prepared for removal by a
phagocytic cell looks most like which of the following?
22) If a cell experiences stress related to the exposure of a certain chemical, the cell will most likely:
F) block the transmission of signals to avoid death.
G) interpret and external signal and self-destruct.
H) receive an internal signal and self-destruct.
J) ignore the messages sent by other cells and harm the body.
23) According to the passage, cells in the body are able to slow the spread of disease by:
A) attacking the infected cells.
B) sending a signal to cells near the infected cells.
C) secreting fluids that repel infection.
D) producing more healthy cells to outnumber the unhealthy cells.
Passage V
Barrier islands are long, narrow sediment deposits that occur offshore, parallel to the shoreline,
and are separated from the land by a shallow body of water, such as a bay or lagoon. Barrier islands are
fragile, dynamic ecosystems that protect coastlines from storm damage and provide critical habitats for
wildlife. Human interference, especially commercial and residential development, has threatened the
resources and diminished the protective roles of barrier islands in order to accommodate this
development. In addition, development in these areas damages vegetation that is necessary for
stabilizing barrier islands, preventing erosion, and preventing migration of the islands toward the shore.
Figure 1 shows the profile of a barrier island.
Figure 1
The natural shifting of barrier islands is influenced by several factors, including waves, currents,
storms, tides, winds, and sea level changes. All of these factors can noticeably move and reshape the
dune area of a barrier island. Human interference is responsible accelerating erosion of protective sand
dune areas, which, over time, magnifies the retreat of coastlines. Figure 2 shows the changes in the
shoreline in meters per year, beginning at Point A (0 km) and extending north. Figure 3 shows the
volume change of protective sand dunes in cubic meters (m 3) per year, beginning at Point A (0 km) and
extending north.
Note: Erosion is the loss of sediment and accretion is the gain of sediment.
Figure 2
Figure 3
24) According to the passage, which of the following is NOT true? The shifting of barrier islands:
F) is magnified by human development.
G) increases as human development on the coastline increases.
H) threatens the habitats of many species of wildlife.
J) reduces the risk of damage caused by storms and tides.
25) Based on the information in the passage, which of the following might occur if barrier islands
continue to be diminished?
A) The vegetation on barrier islands will increase substantially.
B) Human development along the coastline will be able to expand.
C) Buildings along the coastline may suffer greater damage from storms.
D) The body of water between the island and the mainland will increase in size.
26) Which of the following best explains the opposite effect of sand dune volume on the shoreline,
as shown between 0 and 20 km north of Point A in both Figures 2 and 3?
F) The sand dune area is harder to reshape than the shoreline.
G) Strong waves eroded the protective dunes but did not reach the shoreline.
H) The shoreline area naturally erodes more slowly than the sand dune area.
J) Erosion and accretion of barrier islands are not related.
27) Figure 3 shows that dune volume is the lowest:
A) at about 70 km north of Point A.
B) at about 35 km north of Point A.
C) where the shoreline change is least.
D) where the shoreline accretion is greatest.
28) Based on the passage, all of the following are natural causes of barrier island shift, EXCEPT:
F) currents and tides.
G) commercial development.
H) waves and winds.
J) sea level changes.
29) Overwash is created when waves push sediment into the mud-flat area of a barrier island and
the barrier island is shifted closer to the land. Based on this information and Figure 1, which of
the following is most likely true?
A) The height and width of a dune may help to determine how much overwash is able to
collect in the mud-flat area.
B) Barrier islands are not affected by the amount of overwash deposited in the mud-flat area.
C) Barrier islands benefit from larger amounts of overwash in the mud-flat area.
D) Mud-flat areas determine the depth and temperature of the open water.
Passage VI
Several students conducted experiments to investigate certain light characteristics of some
metal compounds. Metal salts that introduced to the blue or white light of a flame produce a color that
is characteristic to that specific metal. When the metal compound comes into contact with the high
temperatures of the flame, the atoms become very excited. The observed colors are due to these
excited atoms, which lose energy and emit visible light as the atoms return to a ground state, or move
from a high-energy level back to a lower-energy level. Table 1 shows several metal salts and the
resulting color that is produced when the metal is introduced to a flame.
Table 1
Metal Salt
Aluminum chloride
Arsenic chloride
Boric Acid
Calcium chloride
Cobalt chloride
Copper chloride
Lithium chloride
Magnesium chloride
Selenium chloride
Sodium chloride
Strontium chloride
Color Produced*
No visible color
Light-blue
Light-green
Orange
No visible color
Emerald
Carmine
No visible color
Azure
Yellow
Crimson
*Notes: Azure = bright purplish blue; Carmine = very bright red; Emerald = very bright green; Crimson =
very deep, dark red (reddish/purple).
Experiment 1
The students used a total of 5 pieces of wire, thoroughly cleaned with hydrochloric acid, rinsed
with distilled water, and dipped into 5 different unknown metal salt powders. A Bunsen burner was lit
and adjusted so that the flame burned clear or blue. The students introduced the wire to the flame and
recorded the color that each metal compound produced. The process was repeated 2 times with each
metal salt (and each wire) and the wire was thoroughly cleaned between trials. Cleaning the wire helps
to ensure that the color of the flame is indicative of the metal salt only, not other compounds that may
also produce colored flames. The students recorded the results of Experiment 1 in Table 2.
Table 2
Metal Salt
A
B
C
D
E
Color Produced
Trial 1
Dark red
Light-blue
Yellow
No color
Orange
Trial 2
Dark red
Light-blue
Yellow
Yellow
Orange
Experiment 2
Several other students were given 5 unknown metal salts and repeated Experiment 1. The
results are shown in Table 3.
Table 3
Metal Salt
F
G
H
I
J
Color Produced
Trial 1
Yellow
Light-green
Bright green
Bright blue
Bright red
Trial 2
Yellow
Light-green
Bright green
Bright blue
Bright red
30) During one the trials, an aluminum chloride sample was accidentally tainted with traces of
sodium chloride. Which of the following best represents when this occurred?
F) Metal Salt A, Trial 1
G) Metal Salt G, Trial 2
H) Metal Salt D, Trial 1
J) Metal Salt D, Trial 2
31) In Experiment 2, Metal Salt F turned out to be cobalt chloride, despite the results. Based on
information in the passage, the color produced in both Trial 1 and Trial 2 was most likely yellow
because:
A) the Bunsen burner flame was too hot for the cobalt chloride.
B) the students failed to properly clean the wires before using them.
C) cobalt chloride often produces a yellow-tinged flame.
D) any defective sample will always produce a yellow flame.
32) According to the passage, Metal Salt J was most likely:
F) strontium chloride.
G) lithium chloride.
H) arsenic chloride.
J) sodium chloride.
33) If the results of Trial 1 in both Experiment 1 and Experiment 2 are accurate, and Metal Salt D is
aluminum chloride, which of the following metal salts was NOT given as an unknown metal salts
in the experiments?
A) Sodium chloride
B) Selenium chloride
C) Magnesium chloride
D) Cobalt chloride
34) Which of the following best explains why the students used a different wire for each metal salt?
F) The hydrochloric acid destroyed the wires upon contact.
G) The blue flames melted the wire during Experiment 1.
H) To avoid contaminating he sample with traces of other compounds.
J) To ensure that the metal salts would corrode the wires.
35) According to the results of the experiments, a flame test could be used to:
A) identify an unknown metal present in a compound.
B) test the strength of wires used in the experiments.
C) determine the melting point of various metals.
D) see how accurate the color spectrum is.
Passage VII
A greenhouse is an artificial structure that functions as an environment for plant life. The
environment of a greenhouse can be tightly controlled, allowing the plant life inside to be protected
from exposure to the natural elements. To maintain an optimal environment, greenhouse operators
must continually monitor and adjust certain factors, such as temperature. A greenhouse replicates the
processes of the atmosphere to regulate temperature; sunlight warms the floor, which, in turn, heats
the air above it as the warmer air rises.
Since the amount of sunlight in an area cannot be controlled, additional climate-control features
must be installed. Greenhouses are normally equipped with a ventilation system in case the
temperature becomes too high, and a heating system so that the air can be warmed if the temperature
becomes too cool. In addition, a typical greenhouse has a plumbing system installed to keep the
moisture of the air and soil at an optimal level.
Table 1 shows the optimal temperatures for various fruits and vegetables at different stages of
development and at different times of day. Germinating plants are just beginning to grow, and
harvesting plants have ripened and are ready to be picked.
Fruit or
Vegetable
Cabbage
Spinach
Lettuce
Tomatoes
Cantaloupe
Zucchini
Germinating
Day
Night
5−6
4−6
7−9
4−7
8−9
5−8
10−12
9−11
17−19
16−18
16−18
16−18
Table 1
Greenhouse Temperature (°C)
Young Plants
Day
Night
12−13
7−8
15−16
8−9
17−20
8−12
25−27
10−14
25−29
18−19
22−26
17−18
Harvesting
Day
Night
12−13
7−8
15−16
8−9
17−20
8−12
21−28
15−18
25−30
18−20
25−30
18−20
Table 2 shows the actual recorded average monthly daytime temperatures of 4 sectors of a greenhouse
for 4 months of a particular year.
Month
1
2
3
4
Sector A
7.2
8.1
7.4
9.0
Table 2
Average Monthly Temperature (°C)
Sector B
Sector C
14.9
26.7
15.1
27.2
16.0
28.1
18.1
30.1
Sector D
15.3
17.2
16.7
19.4
36) According to the passage, the temperature inside of a greenhouse is related to:
F) the number of fruits and vegetables growing in the greenhouse.
G) the amount of natural sunlight available.
H) the type of plumbing system installed.
J) the personal preference of the greenhouse operator.
37) Based on information in the passage, which of the following is most likely true of a greenhouse
ventilation system?
A) Ventilation systems are capable of controlling the amount of sunlight in an area.
B) A greenhouse ventilation system helps to stabilize the temperature inside the greenhouse.
C) Ventilation systems are not necessary in any well-built greenhouse.
D) A greenhouse ventilation system increases the temperature inside the greenhouse.
38) According to the passage, which sector would most effectively support the growth of cantaloupe
crops that are ready to harvest?
F) Sector A
G) Sector B
H) Sector C
J) Sector D
39) According to Tables 1 and 2, Sector A is most suited to:
A) harvesting spinach and zucchini crops.
B) growing zucchini plants.
C) germinating spinach and lettuce crops.
D) harvesting tomato crops.
40) Which of the following best explains the higher average monthly daytime temperatures in all
sectors during Month 4?
F) Crops produce more heat when germinating.
G) Month 4 experienced higher humidity levels.
H) Crops produce more heat closer to harvest time.
J) The ventilation system was not working properly.
Sample Science Test 14 Answers
1)
2)
3)
4)
5)
6)
7)
C
J
C
F
B
G
A
8)
9)
10)
11)
12)
13)
14)
H
D
H
A
F
D
F
15)
16)
17)
18)
19)
20)
21)
C
G
C
J
A
G
B
22)
23)
24)
25)
26)
27)
28)
H
B
J
C
G
B
G
29)
30)
31)
32)
33)
34)
35)
A
J
B
G
C
H
A
36)
37)
38)
39)
40)
G
B
H
C
J