Aging involves multiple harmful biological events that accumulate in different tissues over time and gradually reduce an organism’s state of maintenance and function. Calendar time, however, serves as an imperfect measurement of the physiological processes involved in aging. We all know individuals who are the same chronological age but appear to be very different when it comes to physiological age. Rather than counting years — or gray hairs, for that matter — modern gerontologists turn to biological markers, or biomarkers, of aging. These physiological parameters indicate an individual’s functional level and some biomarkers, such as insulin levels, correlate with mortality. The presence of such biomarkers depends indirectly on patterns of gene expression, which are induced by a variety of internal or external stimuli.
It is pointed out in the passage that the process of aging ____.
can best be determined through biological markers
has a pattern which varies very little among individuals
cannot be clearly understood without taking into account the graying of a person’s hair
is best indicated by the amount of years a person has lived
has an adverse effect on very few functions of an individual’s body
We understand from the passage that biomarkers ____.
do not always produce reliable results in measuring a person’s biological age
are closely related to insulin levels
and calendar time must be taken into account in finding out about a person’s health
are of primary importance for gerontologists in learning about a person’s physical condition
can undermine an organism’s state of maintenance and function
It is clear from the passage that as one ages ____.
one’s genetic defects become more obvious
the body’s ability to maintain itself starts to deteriorate
the physiological processes accurately reflect chronological time
there are functional changes in the body but these are hard to detect
one’s insulin level remains stable
This passage is essentially concerned with ____.
various causes of aging
the damaging effects induced by aging
the significance of biomarkers in measuring the process of aging
the role a person’s genes have in the process of aging