Assignment 2 The Scientific Method
Due January 17
1. Essay (1 point)
Indicate whether you chose a frog or a toad as your species for study and write its scientific name. (You
do not need to italicize the name, since that is difficult to do in WebAssign.)
2. File upload (1 point)
Capture (or download) an image of your amphibian species and upload it to WebAssign.
3. Essay (4 points)
Write a short essay about your amphibian species that indicates:
1) the states in which malformations have been most frequently reported
2) the types of malformations reported
4. True/false (2 points - 0.5 points each)
Based on the paper by Blaustein and Johnson, indicate the truth of each statement by writing the words
true or false in the blank (do not use T or F).
_____ Frogs are good indicators of environmental problems because their permeable skin and shell-less
eggs are directly exposed to potentially harmful agents such as UV radiation.
_____ Increased UV radiation may be a cause of frog malformations, but the increase is due to natural
causes, not to human activities.
_____ The experimental approach has demonstrated that low levels of retinoids (and insecticides with
retinoid-like properties) can produce malformations in frogs.
_____ In some field locations, a correlation has been found between abundance of a frog parasite and
number of malformations in frogs.
5. Essay (4 points)
Based on the paper by Blaustein and Johnson, write a short essay that answers the following questions:
1) Which of the three factors that influence malformations do the authors think is the major cause of frog
malformations?
2) What led the authors to this conclusion?
6. Multiple-choice (1 point)
The model from the paper by Blaustein and Johnson implies that UV radiation and pesticides can
adversely affect frogs
when they come in contact with infected birds
when they come in contact with fertilizers
when they are in a newly constructed pond
when they are in the tadpole stage
none of these are correct
7. Multiple-choice (1 point)
What is the meaning of the dotted line pointing from fertilizers in the model of Blaustein and Johnson?
That the effect of fertilizers is less direct than the effect of parasites on frog mortality.
That fertilizers do not contribute to frog mortality.
That fertilizers influence frog mortality only during the tadpole stage.
That the effect of fertilizers is less important than the effect of pesticides on frog mortality.
That fertilizers cause snails to become infected with parasites.
8. Essay (2 points)
Explain why the authors of the Hyla regilla study used a line graph to show the relationship between
parasite density and mortality, but a bar graph to show the relationship between frequency of abnormality
and parasite infections.
9. Essay (4 points)
Write a short essay that answers the following questions about the Hyla regilla study :
1) What trend (or trends) is/are shown in graph A?
2) Does the trend(s) appear to show a significant correlation? If so, does it correspond to b or c in
figure? (scatterpoint graphs showing different types of trends)
this
10. Multiple-choice (1 point)
What does the Hyla regilla study indicate about the effects of different parasites on frogs?
The parasite Ribeiroia plays a greater role in causing frog malformations than Alaria.
The parasite Ribeiroia causes no observable frog malformations.
The parasite Ribeiroia causes fewer frog deaths than Alaria.
Infection with either of the parasites can cause a significant number of frog malformations
relative to the control group.
Infection with either of the parasites can cause a significant number of frog deaths relative to the
control group.
11. Multiple-choice (1 point)
In the Hyla regilla study, what happens if frogs are infected with both parasites at the same time?
There are more malformations than produced by Ribeiroia alone.
There are more frog deaths than produced by Ribeiroia alone.
The number of malformations is about the same as produced by Alaria alone.
The number of malformations is about the same as produced by Ribeiroia alone.
The number of frog deaths is not significantly different from the control group.
12. File upload (4 points)
Fill out the table on your worksheet (with "yes" or "no") as you review the website on amphibian
deformities. Use your screen shot technique to capture an image of the completed table, then submit
the image below. (Do not submit a doc file, since these are difficult to grade in WebAssign.)
NOTE: You may use links in the navigation bars to answer questions about the website.
Criteria
Credibility
Is there an author listed? (Be careful the author can be an organization)
Does the author cite sources or a bibliography?
Does the author cite formal credentials or experience?
Can you contact the author?
Do you know who sponsored the page? Are they reputable?
Bias
Does the site present information in an objective manner?
Are all sides of an issue represented, or is this site biased?
Audience
Is the level of the website appropriate to your needs?
Does the content cover several topics at some level? (as opposed to only one topic in detail)
Accuracy
Does the site provide documentation for the information provided?
Does the site include a detailed explanation of its research methods?
Currency
Was the website published or updated recently?
Relevance
Does the information add to or support your research?
Does the site provide additional links that are also useful?
Does the page provide less information than you need?
13. Multiple-choice (1 point)
The Amphibian Declines website suggests that the most important cause of the
recent decline in amphibian populations (aside from habitat destruction) is
UV radiation
parasitic infection
contamination by insecticides
contamination by fertilizers
infection by a fungus
14. Multiple-choice (1 point)
The Amphibian Declines website indicates that approximately _____ of the world's amphibian species are
threatened.
1%
10%
30%
50%
100%