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pollen when wind speeds are low or when humid
conditions prevail. Recent studies suggest another way in
which species compensate for the inefficiency of wind
pollination. These studies suggest that species frequently
take advantage of the physics of pollen motion by
generating specific aerodynamic environments within the
immediate vicinity of their female reproductive organs. It
is the morphology of these organs that dictates the pattern
of airflow disturbances through which pollen must travel.
The speed and direction of the airflow disturbances can
combine with the physical properties of a species' pollen
to produce a species-specific pattern of pollen collision on
the surfaces of female reproductive organs. Provided that
these surfaces are strategically located, the consequences
of this combination can significantly increase the
pollen-capture efficiency of a female reproductive organ.
A critical question that remains to be answered is
whether the morphological attributes of the female
reproductive organs of wind-pollinated species are
evolutionary adaptations to wind pollination or are merely
fortuitous. A complete resolution of the question is as yet
impossible since adaptation must be evaluated for each
species within its own unique functional context.
However, it must be said that, while evidence of such
evolutionary adaptations does exist in some species, one
must be careful about attributing morphology to
adaptation. For example, the spiral arrangement of
150 6.The author of the passage is primarily concerned 8. The passage suggests that the recent studies cited in the with discussing second paragraph have not done which of the following? (A) the current debate on whether the morphological (A) Made any distinctions between different species attributes of wind-pollinated plants are of wind-pollinated plants. evolutionary adaptations (B) Considered the physical properties of the pollen (B) the kinds of airflow patterns that permit wind- that is produced by wind-pollinated plants. pollinated plants to capture pollen most effi- (C) Indicated the general range within which plant- ciently generated airflow disturbances are apt to (C) the ways in which the reproductive processes of occur. wind-pollinated plants are controlled by (D) Included investigations of the physics of pollen random events motion and its relationship to the efficient (D) a recently proposed explanation of a way in capture of pollen by the female reproductive which wind-pollinated plants reduce pollen organs of wind-pollinated plants. waste (E) Demonstrated that the morphological attributes (E) a specific morphological attribute that permits of the female reproductive organs of wind- one species of wind-pollinated plant to pollinated plants are usually evolutionary capture pollen adaptations to wind pollination. 7. According to the passage, the "aerodynamic 9. It can be inferred from the passage that the claim environments" mentioned in the second paragraph, tha...
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- Fall '13