Mucous is the adjectival form of the more familiar noun, mucus. In other words, mucous is actually the action or ability to make the yucky stuff we blow into tissue, which is mucus. There are mucous cells, mucous fluid, mucous membranes, and mucous glands. They are all different objects that can secrete mucus.
  Thus, if you have business income, you can contribute to your ROTH IRA if you are eligible and a SEP IRA. If your SEP IRA is likely to become substantial or you have funds in a 401(k) from a previous employer and you are an one person (or one person with a spouse) business, you should look into individual 401(k)s.
Also, as with traditional (but not Roth) IRAs, you must begin taking distributions from the account once you turn 70-1/2. You can start earlier, without penalties, beginning at age 59-1/2. The SEP-IRA's contribution limits separate it from traditional and Roth IRAs -- in a big way. The more prevalent IRAs have a contribution limit of $5,500 for 2017, plus a $1,000 catch-up contribution for those aged 50 and older.