system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Is there an advantage of any particular blood group over the other?
gpt
O-type blood provides a bit of resistance to malaria. Also, some blood types are much more valuable for blood donation. O- blood can be donated to 100% of the U.S. population, and O+ blood can be donated to 84%, so people with those blood types are encouraged to donate blood as much as they can. On the other hand, people with AB- or AB+ blood are universal plasma donors, so they're encouraged to donate plasma instead of blood.