Reading Comprehension

Recently biologists have been
interested in a tide-associated
periodic behavior displayed by
Line the diatom Hantzschia virgata, a
(5) microscopic golden-brown alga that
inhabits that portion of a shoreline
washed by tides (the intertidal zone).
Diatoms of this species, sometimes
called "commuter" diatoms, remain
(10) burrowed in the sand during high
tide, and emerge on the sand sur-
face during the daytime low tide.
Just before the sand is inundated by
the rising tide, the diatoms burrow
(15) again. Some scientists hypothesize
that commuter diatoms know that it
is low tide because they sense an
environmental change, such as an
alteration in temperature or a change
(20) in pressure caused by tidal move-
ment. However, when diatoms are
observed under constant conditions
in a laboratory, they still display
periodic behavior, continuing to bur-
(25) row on schedule for several weeks.
This indicates that commuter diatoms,
rather than relying on environmental
cues to keep time, possess an inter-
nal pacemaker or biological clock
(30) that enables them to anticipate peri-
odic changes in the environment.
A commuter diatom has an unusu-
ally accurate biological clock, a
consequence of the unrelenting
(35) environmental pressures to which
it is subjected; any diatoms that do
not burrow before the tide arrives
are washed away.
This is not to suggest that the
(40) period of this biological clock is
immutably fixed. Biologists have
concluded that even though a
diatom does not rely on the envi-
ronment to keep time, environmental
(45) factors-including changes in the
tide's hydrostatic pressure, salin-
ity, mechanical agitation, and
temperature-can alter the period
of its biological clock according to
(50) changes in the tidal cycle. In short,
the relation between an organism's
biological clock and its environment
is similar to that between a wristwatch
and its owner: the owner cannot
(55) make the watch run faster or slower,
but can reset the hands. However,
this relation is complicated in intertidal
dwellers such as commuter diatoms
by the fact that these organisms are
(60) exposed to the solar-day cycle as
well as to the tidal cycle, and some-
times display both solar-day and
tidal periods in a single behavior.
Commuter diatoms, for example,
(65) emerge only during those low tides
that occur during the day.

According to the passage, each of the following is characteristic of the tide-associated periodic behavior of commuter diatoms EXCEPT:

A. It is triggered when the diatoms are inundated by the tide
B.It is correlated with the rise and fall of the tide
C. It adjusts to changes in the tidal cycle
D.It is influenced by the solar-day cycle
E.It is regulated by an innate time-keeping mechanism

Please provide explanation with answer.

It think the correct is A

The passage states that diatoms burrow just before the shore is inundated by tides not that their behavior is triggered on getting inundated by tides.

BY elimination you can pin point to A

All the other points are mentioned in the passage.

B- Line 10-15
C- Line 61
D- Line 60
E- Line 31

Hope that helps.

OA - A for the above question.

Which of the following can be inferred from the passage about the effect of the solar-day cycle on the tide-associated periodic behavior displayed by commuter diatoms?
A The solar-day cycle makes this behavior less advantageous to the commuter diatoms at certain times of the year.
B The solar-day cycle makes this behavior somewhat more erratic.
C The solar-day cycle makes this behavior less important to the survival of the commuter diatoms.
D Because of the solar-day cycle, this behavior is forced to proceed at a more rapid pace at certain times during the 24-hour day.
E Because of the solar-day cycle, this behavior is not expressed at certain times during the 24-hour day.

Please provide answer with explanation.

greenwich wrote:OA - A for the above question.

Which of the following can be inferred from the passage about the effect of the solar-day cycle on the tide-associated periodic behavior displayed by commuter diatoms?
A The solar-day cycle makes this behavior less advantageous to the commuter diatoms at certain times of the year.
B The solar-day cycle makes this behavior somewhat more erratic.
C The solar-day cycle makes this behavior less important to the survival of the commuter diatoms.
D Because of the solar-day cycle, this behavior is forced to proceed at a more rapid pace at certain times during the 24-hour day.
E Because of the solar-day cycle, this behavior is not expressed at certain times during the 24-hour day.

Please provide answer with explanation.

Thanks for providing the OA and another question on this RC.

To answer this question I concentrated on lines 55-66

My Approach

- eliminate A as no where it mentions about advantages.
- Eliminate B as somewhat more erratic is too strong of a word
- Eliminate C as it does not talk about importance

Its between D & E for me.

I would eliminate D because in line 55 - the owner cannot make the watch run faster or slower

I would choose E

OA plz

OA - E

Line 55 helps.

Option A