Biology Now, 2e

Here and Gone ■ 391

(^8) Place the following elements of the scientists’ study of oceanic
phytoplankton levels in the correct order from earliest to latest by
numbering them from 1 to 5.
a. Boyce analyzed data from multiple sources showing that
ocean phytoplankton levels have declined dramatically over
the last 100 years.
b. Worm demonstrated that industrialized fishing had deci-
mated predatory fish communities.
c. Secchi designed a device to measure phytoplankton levels
in water.
d. Boyce’s finding of declining phytoplankton levels was chal-
lenged by fellow scientists, because of his methodology.
e. Boyce, a graduate student in Worm’s lab, decided to study how
the loss of predatory fish reverberated through the oceanic
ecosystem—in particular, its phytoplankton populations.
(^9) How is an ecosystem different from an ecological community?
Tr y Something New
(^10) In the energy pyramid shown here, an owl, a cardinal, and
a grasshopper are the fourth, third, and second trophic levels,
respectively.
a. If each grasshopper passes 100 Kilocalories to the cardinal
when eaten, how many grasshoppers would the cardinal have to
eat to obtain 10,000 Kilocalories?
b. How many Kilocalories of grass are required to produce 10,000
Calories’ worth of grasshopper?
c. Where does the lost energy go?
(^11) Is the water cycle (see Figure 18.12) more similar to the
movement of energy or to the movement of nutrients through an
ecosystem? Justify your answer.
(^12) While sloshing around in the swampy wetlands of a nearby
forest preserve, a small child notices a rotting tree branch
covered in fungi. What are these organisms doing on this tree
branch?
(a) These are producers acquiring energy through photosynthesis.
(b) These are consumers acquiring energy from the wood and
releasing nutrients back to the earth.
(c) These are decomposers acquiring energy from the wood and
releasing nutrients back to the earth.
(d) These are decomposers releasing nutrients back to the earth,
but acquiring no energy for themselves in the process.
Leveling Up
(^13) Write Now biology: human-caused biome shifts The location of
Earth’s different biomes depends on climate and altitude, for the
most part. However, human activities play a role in the conversion
of one biome to another, as has been seen many times in history.
Research one major change in a biome category based on human
activity, and describe how and why this change happened.
Speculate on how this change could have been specifically
avoided. (Note: Do not analyze a change via deforestation to
agricultural land, since agricultural land is not a natural biome.
Hint: Take a look at Easter Island as one example.)
(^14) Doing science Join forces with millions of others by classifying
phytoplankton on your computer. Do an Internet search for
“citizen science phytoplankton” and sign in as a citizen scientist,
complete the tutorial, and start helping researchers quantify the
phytoplankton in our oceans.
(^15) What do you think? Some people think the current U.S.
Endangered Species Act should be replaced with a law designed
to protect ecosystems, not species. The intent of such a law
would be to focus conservation efforts on what its advocates
think really matters in nature: whole ecosystems. Given how
ecosystems are defined, do you think it would be easy or hard
to determine the boundaries of what should and should not
be protected if such a law was enacted? Give reasons for
your answer.
For more, visit digital.wwnorton.com/bionow2 for access to:
Trophic level Energy (Kilocalories)
Tertiary consumer =
fourth trophic level

10

100

1,000

10,000 Kcal

Secondary consumer =

third trophic level

Primary consumer =

second trophic level

Producer =

first trophic level

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