TERM 1
life
span
DEFINITION 1
The upper boundary of life, the maximum number of years
an individual can live. The maximum of human beings is
about 120 to 125 years of age.
TERM 2
life expectancy
DEFINITION 2
The number of years that will probably be lived by the
average person born in a particular year.
TERM 3
cellular clock theory
DEFINITION 3
Leonard Hayflick's theory that the maximum number of times
that human cells can divide is about 75 to 80. As we age, our
clls have less capability to divide.
TERM 4
free-radical theory
DEFINITION 4
A microbiological theory of aging that states that people age
because inside their cells normal metabolism produces
unstable oxygen molecules known as free radicals. These
molecules ricochet around inside cells, damaging DNA and
other cellular structures.
TERM 5
mitochondrial theory
DEFINITION 5
The theory that aging is caused by the decay of
mitochondria, tiny cellular bodies that supply energy for
function, growth, and repair.
