You have lots of options related to biology, chemistry, both biology and chemistry, and other fields.
Medical field is very wide. You can enter it and choose any area of specialisation such as surgery, pediatrics, dentistry, neurology, obstetrics and gynecology, ophthalmology, dermatology, physiology, psychiatry, radiology, veterinary, and so on.
Aeronautics is related to mathematics and physics more. If you really like aeronautics itself, then go for it. But choose an institute which provide extensive practical experience apart from sound theoretical knowledge; since it is a highly specialised field and technical competency is most significant.
More courses related to biology(most of these are research based):
biology, zoology, botany, microbiology, biotechnology, genetics, dietary, pharmacology, bio-statistics, forensic science
Chemistry has career options involving chemical analysis and development which may be related to industry, agriculture, food, medicine, or environment. Courses related to chemistry: chemistry, chemical engineering, biochemistry, environmental science, oil and petrol, pharmaceuticals, food science, forensic science, etc.
[Answered on May 27, 2014]