A mutation is a change that occurs in our DNA sequence, either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light and cigarette smoke.
If you were born in 1929 or later, you need to work at least 10 years to become eligible for Social Security. The SSA determines eligibility with a system of credits. Basically, you earn up to four credits for every year worked, and you need a total of 40 credits to qualify for Social Security.
Qualifying for Retirement Benefits. To qualify for retirement, you must have at least 40 work credits by the time you get to full retirement age. You earn a work credit by making a certain amount of money ($1,130 in 2012) from a job or from self-employment, and paying Social Security taxes on that income.f you're on disability, Social Security closes your case when you reach full retirement age, and it simply renames the benefits retirement.. You don't have a choice in the matter, and you can't draw both disability and retirement.