Different types of blood contact different kinds of antigens and antibodies. For example, Type A blood has A antigens and B antibodies, antibodies being the thing that fights B antigens. Type B blood has B antigens and A antibodies. So if someone with type B gets transfused with Type A blood, the person's antibodies will attack the new blood.
Yes It's Possible for a curved path to move by force
Mendel's Law of Segregation states that every organism has two alleles per trait and that these alleles separate during meiosis, so each gamete gets one allele.