Whole or Term?

A couple of months ago I made an inquiry online to get a quote on life insurance policies. The biggest question I had was which is better to purchase after the age of 50, whole life or term life insurance policy? While whole life insurance seems to be the choice of many at an early stage in one's life, it might make more sense for someone after 50 to choose term life which might serve them better. My concern is that if longevity is predominant in our genes, then why not go for the whole life policy? My great-grandfather lived to be 97, and his daughter, my grandmother lived to be 93. That means if I chose term life it would run out when I am either 72, 77, or 82. Can you do an additional thirty years if necessary, and if so does the cost stay the same? I've not received an answer to my questions, so which one would you choose?