Answer:
ABO blood grouping system is based on presence or absence of three types of antigen on red blood cells. A and B blood group have A and B antigens respectively. AB blood group has both A and B antigens. O blood group does not have any antigen. 
A body with particular blood type will consider other blood group foreign ( because it has different antigen ) and produce antibodies against it. A person with blood type A can not be given B type blood because the antibodies in his body will destroy RBCs with B antigen which may even prove fatal. 
AB blood type person can receive blood from both A and B blood groups because he has antigens for both of them so it will produce antibodies for neither of them. He can also receive O type blood because O blood does not have any antigen so it can be given to any person without incompatibility reaction.  
However, AB individual can only donate blood to AB individual because his blood cells have both A and B antigens. So, he can only donate blood to an individual who does not produce antibodies for both A and B blood groups and that would only be another AB blood type individual. 
 
        
             
        
        
        
Answer:
Explanation:
Parrotfish spend 90% of their day cleaning the reef of algae. This cleaning (eating) helps corals grow and thrive, and healthy reefs support more fish in the sea. ... They snack on the hard parts of coral which becomes a white sandy material in their stomachs that they leave behind on the reef.
 
        
             
        
        
        
Answer:
Consistently changes the subject when the topic of the fetus/newborn is raised.
Explanation:
This is the decision of the couple whether they want a child or not and can discuss about the family planning as well. Different psychological aspects acn explain this matter.
The expectant father is not mentally prepared for the child. He might refuse the talks and stay away from the communication that are related to the new born child. This must be properly assessed and important to understand the feeling of the expectant father.  
Thus, the answer is consistently changes the subject when the topic of the fetus/newborn is raised.
 
        
             
        
        
        
The cycle that is described in the problem is called the water cycle. in this cycle, the water from a lake is evaporated through the heat of the sun and the water is accumulated in the clouds. When the clouds are saturated, then water condenses and precipitates to fall as rain.
        
             
        
        
        
Assuming that Element X is neutral or the atom of element X is neutral or uncharged it will possess the same number of electrons which is 80.