
Biology is not silly at all. That's a stupid statement. I did, however, agree with most of the rest of your post.
It is extremely important to know how we work, and how things interact in an environment. This helps us make efforts to conserve our environment, which is extremely important. You can't help something that you can't understand (what do you think medicine and psychology are?). Biology is just as important (and quite often related to those). Just look at all the interesting things that spring from an advanced knowledge of biology, all the interesting research. We can extend our life almost indefinately just by somehow introducing Telomerase (an enzyme that reproduces moot genetic information on the end of Chromosones used for protection). Just one enzyme in our cells can increase our life-span by like 20 years. If we figure out how to disrupt the action of Telomerase in cancer cells, it's a cure for (fatal) cancer. I'm speaking theoretically here, but what if?
And let's not ignore the current and past research stemming from biology that make my life and yours much more pleasant. Biology is extremely important and extremely relevant. Even if you don't care about Mendelian genetics, the other stuff is so useful.