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.
Answer:
The answer is 3. Double Helix.
bacteria are classified into 5 groups, spherical (cocci), rod (bacilli), spiral (spirilla), comma (vibrios) or corkscrew (spirochaetes).
يعينك على خير ان شاءالله يارب وياك يارب وياك يارب وياك يارب وياك يارب وياك يارب وياك يارب وياك يارب وياك يارب وياك يارب وياك يارب وياك يارب وياك يارب وياك