Chapter 1 - The Web Of Life

Front 1

Scientists were especially worried about amphibians for three reasons:

Back 1

First, the decline appeared to have started recently across wide regions of the
world.

Second, some of the populations in decline were located in protected or
pristine regions, seemingly far from the effects of human activities.

Third, many
scientists view amphibians as good “biological indicators” of environmental
conditions for a number of reasons.

Front 2

Thus, to understand how natural systems
work, we must understand ____.

Back 2

ecology

Front 3

what is ecology

Back 3

the scientific study of
how organisms affect—and are affected by—other organ-
isms and their environment

Front 4

As a result, even
species that do not interact directly with each other can be
connected indirectly by shared ------ of their --------.

Back 4

features, environment

Front 5

Early observations suggest that -----cause
amphibian deformities

Back 5

parasites

Front 6

Sessions found that the deformed amphibians all
contained a parasite, now known to be Ribeiroia ondatrae,
a -------- ---------.

Back 6

trematode flatworm

Front 7

As an initial
test of this hypothesis, they implanted --------------
near the developing limb buds of tadpoles.

Back 7

small glass beads

These beads
were meant to mimic the effects of Ribeiroia, which often
produces cysts close to the area where limbs form as a
tadpole begins its metamorphosis into an adult frog. In
a 1990 paper, they reported that the beads caused defor-
mities similar to those found by Ruth.

Front 8

What did johnson find in the pond that was an intermediate host for the trematode flatworm parasite?

Back 8

snail

Front 9

was this finding indirect or direct result that the flatworm caused deformities?

Back 9

indirect

Front 10

Johnson and his colleagues found that as the number
of parasites increased, ----- of the tadpoles survived to
metamorphosis, and more of the survivors had -------
(Figure 1.4).

Back 10

fewer, deformities

Front 11

review page 32

Back 11

~

Front 12

in the experiment with mesh cages and pesticides, what were the two ultimate results?

Back 12

Overall, the results
of this experiment indicated that (1) exposure to Ribeiroia
was necessary for deformities to occur, and (2) when frogs were exposed to Ribeiroia, deformities were more common
in ponds with detectable levels of pesticides than in ponds
without detectable levels of pesticides.

Front 13

pesticides might decrease the ability of frogs to resist --------- by parasites.

Back 13

infection

Front 14

Review table 1.1 on page 35

Back 14

_