ACT science practice test 68

Directions: Each passage is followed by several questions. After reading a 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.


Pertussis, commonly known as whooping cough, is a highly infectious disease of the respiratory tract caused by bacteria. The disease spreads by direct contact with secretions from the nose or throat of an infected person, or by breathing in the air when an infected person coughs. Pertussis most easily passes between people in the initial stage of illness, but it can be spread at any time during the course of the illness. Figure 1 depicts the course of pertussis from exposure to recovery.

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Figure 1

The number of reported cases of pertussis from 1974 through 2004 is depicted in Figure 2.

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Figure 2

The number of reported cases of pertussis in 2004 by age group is shown in Figure 3.

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Figure 3

1. A new vaccine for pertussis was introduced in 1991, which claimed to be more effective than the previous vaccine. Does the data in Figure 2 support this claim?

A. No. Rates of pertussis increased after 1991.
B. No. Rates of pertussis remained the same after 1991.
C. Yes. Rates of pertussis decreased after 1991.
D. Yes. Rates of pertussis increased after 1991.

2. If a person was experiencing a cough, was medicated, and was still contagious, he or she would be in what stage of the disease?

F. Incubation
G. Catarrhal
H. Paroxysmal
J. Convalescent

3. What is the maximum number of weeks that pertussis can be transmitted?

A. 1
B. 3
C. 8
D. 12

4. Doctors hypothesized that because of their immature immune systems young children are the most susceptible to pertussis. Does the data from 2004, in Figure 3, support this theory?

F. No. Pertussis mostly affects the elderly.
G. No. Ten- to fourteen-year-olds were the most likely to contract pertussis.
H. Yes. Infants had the highest rate of pertussis.
J. Yes. Seven thousand young children contracted pertussis.

5. Which of the following statements could be a plausible explanation for increased incidence of pertussis?

A. Fewer infants are being vaccinated for pertussis, and are therefore contracting the disease.
B. Regulations on reporting pertussis are more lax now, so the numbers are inaccurate.
C. There are more blood transfusions performed now, increasing people’s risks of contracting pertussis.
D. Vaccine immunity wanes after 5–10 years, so more young adults are succumbing to pertussis.

6. Which of the following statements about pertussis is NOT true?

F. The disease has an incubation period ranging from 1 to 3 weeks.
G. Symptoms are similar to those of a common cold.
H. The disease is a virus that cannot be treated with antibiotics.
J. Pertussis can be communicated via particles left in the air after a person coughs.

Scientists examined several ingredients commonly used as active agents in sunscreen. The goal of the study was to determine which ingredients are most effective at blocking harmful UV rays.

Scientists used PABA, oxybenzone, octyl salicylate, and a broad-spectrum commercial sunscreen (SPF 45). The samples were exposed to sunlight with wavelengths ranging from 240 to 440 nm. The percent transmittance of UV rays at each wavelength was recorded. The data was collected manually using a spectrophotometer. The results, in 20-nm increments, are shown in Table 1.

Table 1

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Figure 1 displays the intensity of sunlight across the spectrum.

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Figure 1

In 1975, Thomas B. Fitzpatrick, MD, Ph.D., of Harvard Medical School, developed a classification system for skin type. This system was based on a person's complexion and responses to sun exposure. Table 2 lists the skin types and their characteristics.

Table 2

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7. According to Table 1, which substance had the highest percent transmittance of UV rays for sunlight with a wavelength of 260 nm?

A. Octyl salicylate
B. PABA
C. Oxybenzone
D. Commercial sunscreen

8. Based on the information in Figure 1, sunlight is most intense at which of the following wavelengths?

F. 290 nm
G. 300 nm
H. 320 nm
J. 340 nm

9. A person with fair skin tone, whose skin burns but also tans slowly, likely has which of the following skin types?

A. Type I
B. Type II
C. Type III
D. Type IV

10. Experts state that anyone whose skin is sensitive or very sensitive to UVA should always wear sunscreen. According to Table 2, people with which skin types should always wear sunscreen?

F. Types I and II
G. Types I, II, and III
H. Types II, III, and IV
J. Types V and VI

11. In sunlight with an irradiance of 0.01 W/m2/nm, oxybenzone would be expected to have a UV ray percent transmittance of:

A. 3.8
B. 5
C. 9.7
D. 100