Biology is a broad subject that provides knowledge of life itself. If you are interested in the living world, then this is the right subject for you.
Many areas of society are working on sustainable development and greening their activities. Knowledge of biology and ecology are important components in this, so a good understanding of Biology can be useful in many professional fields, regardless of your degree specialisation.
Södertörn University offers a number of freestanding courses in the subject. They have a general focus on biology, including the philosophy of biology, physiology and ecology.