Chapter 17, Physical development in
late adulthood Test Bank.
life span - Answer the length of time an organism is expected to live
life expectancy - Answer the number of years a person can expect to live
Centenarians - Answer people who live past 100 years of age, the numbers of which are
increasing by 7% each year
factors that influence longevity - Answer - genetics, environmental factors including lifestyle,
ethnic differences, gender, marital status,
Telemores - Answer stretches of noncoding DNA at the ends of chromosomes
evolutionary theory of aging - Answer natural selection has not eliminated many harmful
conditions and nonadoptive characteristics in older adults
cellular clock theory - Answer Leonard Hayflick's theory that the maximum number of times
that human cells can divide is about 75 to 80. As we age, our cells have less capability to divide.
free-radical theory - Answer A microbiological theory of aging stating that people age because
when their cells metabolize energy, they generate waste that includes unstable oxygen
molecules, known as free radicals, that damage DNA and other structures.
mitochondrial theory - Answer aging is caused by the decay of mitochondria
Sirtuins - Answer A family of proteins that have been proposed as having important influences
on longevity, mitochondrial functioning in energy, calorie restriction benefits, stress resistance,
and a lower incidence of cardiovascular functioning.
mTOR pathway - Answer a cellular pathway involving the regulation of growth and metabolism
that has been proposed as a key aspect of longevity