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.
To qualify for Social Security retirement, you must work and earn at least 40 work credits, by paying in to the Social Security system through payroll taxes. You can earn a maximum of 4 credits every year. If you don't have the work credits, then you can't draw any retirement.