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.
In 2015, a worker must earn $1,220 to earn one work credit. In order to qualify for Social Security Disability benefits, you will generally need to have earned a total of 20 work credits, although there are age exceptions to this rule.or example, disability applicants who are under 24 years of age may be able to qualify for Social Security Disability benefits if they have earned a total of six work credits in the three years prior to the onset of the disability.