Biology Now, 2e

A Critical Choice ■ 37

contagious even when an infected person shows no symptoms,

and symptoms may not appear until years after infection. Some

but not all strains of HPV can cause genital warts and cancer.

The HPV vaccine is very effective and is recommended for all young

people from the ages of 11 to 26 years. What steps would you go

through to decide whether to vaccinate yourself or your child with

the HPV vaccine? (Hint: Use the method for evaluating scientific

claims, including assessing real science versus pseudoscience.)

Leveling Up

(^13) Life choices Most American universities require students to
have the following immunizations: MMR (measles, mumps, and
rubella), varicella (chicken pox), and Tdap (tetanus, diphtheria,
and pertussis/whooping cough). Most also recommend or require
hepatitis A and B, meningococcal conjugate (meningitis), HPV
(human papillomavirus), poliovirus, and the annual flu vaccine.
a. Which of these vaccines have you received?
b. If you have not received one or more of them, why not?
c. Some school districts allow parents to “opt out” of vaccines
because of their belief system. Do you think this option should
be allowed for university students? Why or why not? What are
the possible consequences of allowing people to opt out of
vaccinations?
(^14) Write Now biology: evaluating scientific claims John Oliver, in
a 2014 episode of Last Week Tonight, discussed a poll finding that
one in four Americans is skeptical of global climate change. He
dismissed the poll results and compared it to a poll asking, “Which
number is bigger, 15 or 5?” or “Do owls exist?” Why does Oliver feel
that what the American public believes about climate change is not
relevant? (Hint: It could be argued that each of the people polled
was making a scientific claim, either in support of or against the
scientific consensus on climate change.)
(^15) Is it science? Watch the 2011 movie Contagion, which depicts
the spread of a fictional virus. While watching the movie, make a
list of the scientific concepts that are presented, and note whether
you think they represent real science or pseudoscience. Then use
your textbook and Internet research to determine whether you were
correct or incorrect in each case. If you evaluated any of the concepts
incorrectly, reflect on how you came to your initial conclusions.
(^16) What do you think? Read Peg Kehret’s novel Small Steps: The
Year I Got Polio, the author’s true account of contracting polio
as a seventh-grader. Keep a reflective journal while reading the
book, documenting your emotional reactions to each chapter in
this story. While reading, also note where you learned something
new that you did not know previously about the poliovirus, the
symptoms of polio, and the treatment options (or lack thereof) in
the late 1940s. In your final entry, please reflect on how this novel
did or did not change your feelings toward vaccination.
a zoomed-in view of 1990–2012. The second graph organizes the data
by age group from 1990 to 2012. (The 2013 data are not complete in
either graph.) DTP, Tdap, and DTaP are different formulations of the
vaccine that covers tetanus, diphtheria, and pertussis.

192219301940195019601970198019902000 2013

Year

DTP

300,000

0

50,000

100,000

150,000

200,000

250,000

Number of cases

1990199520002005 2013

60,000

0

10,000

20,000

30,000

40,000

50,000

DTaP

Tdap

1990 1995

<1 yr

1–6 yr

7–10 yr

11–19 yr

20+ yr

2000 2005 2013

Year

0

40

20

60

80

100

120

140

Incidence rate(per 100,000)

a. Describe what the first graph shows. What do each of the axes

represent? What does any point on the line show? What general

trend is seen, if all the data shown in the graph are considered?

b. Why do you think there was an increase in cases of pertussis in

the first decade of the twenty-first century?

c. Describe what the second graph shows. What do each of the

axes represent? What does any point on each of the different

lines show? What general trend is seen, if all the lines are

considered? What differs among the lines?

d. Compare the incidence of pertussis cases in children under

1 year old and people over the age of 20.

e. Summarize your reflections on reviewing these graphs and

the relative risks of pertussis and the pertussis vaccine. What

would you recommend to someone trying to decide whether to

vaccinate a child?

(^12) Human papillomavirus (HPV) is the most common sexually
transmitted disease in the United States; almost all sexually
active people are infected with HPV at some point. HPV can be
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