Answer:
sea floor spreading occurs at mid ocean ridges
Increase over time because it is moving away from each other.
*Sea floor spreading
Answer:
a. Type O blood - No A or B antigens on RBCs-Anti-A antibodies in plasma-Anti-B antibodies in plasma
b. Type A blood - A antigen on RBCs- Anti-B antibodies in plasma
c. Type B blood - B antigen on RBCs- Anti-A antibodies in plasma
d. Type AB blood - A antigen on RBCs- B antigen on RBCs- Neither anti-A or anti-B in plasma
Explanation:
ABO blood grouping system represents multiple allelism which was discovered in humans by Karl Landsteiner. The blood group is determined by the presence or absence of A & B antigens and antibodies.
The 4 blood groups which exist in ABO system are O, A, B and AB. Also, allele A and B are co-dominant i.e. if they both will exist on the surface of an RBC then both will be equally expressed which implies that there will be no dominant or recessive allele.
Type O blood group has H antigen on the surface of RBC and has both the antibodies i.e. antibody A and B. The absence of antigens A and B makes it a universal donor.
Type A blood group has A antigen on RBC and has antibody B in the plasma.
Type B blood group has B antigen on RBC and has antibody A in the plasma.
Type AB blood group has both the antigens i.e. antigen A and B on RBC and does not have any antibody in the plasma which makes it a universal acceptor.
