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.
Trial Work Period. You can attempt to work for a period of nine months over the course of five years. Social Security does not require consecutive months. You must report your work activity and continue to have a disability. A trial work month is one in which you earn $720 or more.