The variations might help the organism to survive if there is a change in its environment
Eg heat resistant bacteria
The variation might help the organism survive predators
Eg. Green beetles blend with green leaves thus disabling crows to spot them
:)
The box will move to the right
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.