Bacteria science question

considering that garlic grows under ground, why would it be beneficial for garlic to develope the ability to kill bacteria?

Why does Raw Garlic kill bacteria better than cooked garlic?


two pretty easy questions, but im not exaccctlyyy sure why. i have an idea, but it would be helpful if you could give me a few hints? :) thanks in advance! and no rude comments please

Bacteria are very common in the soil. They decompose plant matter. The plant doesn't want its bulbs digested by bacteria so it inhibits their growth.

Allicin is a primary antibiotic. It decomposes when cooked.
"Furthermore, allicin can be unstable, breaking down within 16 h at 23 °C."

http://en.wikipedia.org/wiki/Allicin