Is life sciences are all about research? the answer is NO!
Lets us have a great deep insight on the fields of biology-the ever enchanting life sciences!
Molecular biology - Yes, you will mess around with the DNA. You play with the genetics and look for new phenotypes which would tell you about the function of proteins/RNA/DNA region in cells (in vivo).
Biochemistry/Biophysics - In general, more quantitative. In general, you isolate/purify your favorite protein/DNA/RNA from the cell, and investigate their functions in a test tube (in vitro). You look at how the molecules move, how they do the chemistry, how they interact with other molecules.
Microbiology is generally the science of germs. You study the behaviors of germs. Usually, you would use methods in molecular biology and biochemistry. Virology, the science of virus.
Bio engineering is a wide field too... megabigBLUR described part of it. One other specializations involved making machines/body parts for biomedical purposes, either for research or for treatment (i.e. synthetic arms and so forth, new methods for scanning brains, or a faster way of sewing wound together).
So, just a piece of advice. If you like biology and hate math in high school. Molecular biology/ cell biology might be want you want. If you like chemistry/biology/quantitative analysis, you can look into biochemistry, chemical biology kind of thing. If you are a hardcore chemist, just do chemistry. Chemists play an IMPORTANT role in the biotech industry too (they make all our drugs). People who likes physics a lot, think about the biological system, the physics that nature uses to create life is incredible and fascinating.
And it doesn't matter very much what you study as an undergraduate. It just gives you a taste of each specific fields. It's not too late to switch field in graduate school. If you look at the famous biologists nowadays, there are very very few examples where what they are doing now is what they do in undergraduate. In fact, many of them study math, chemistry or physicsts as an undergraduate. Furthermore, the field today has become extremely interdisciplinary, you need to be good at almost anything, and be willing to move away from your niche to apply the most suitable technique to the problem you want to solve.
In addition, as the field of system biology/ quantitative biology continues to grow, the biological field will welcome more and more mathematicians and computer scientists. So, if you are trying to be a biologist today, make sure that you at least know some math and programming, otherwise, you aren't going to catch up with the influx of results from system biology in the close future.
