Answer:
C
Explanation:
The brother has different alleles for the blood type gene than his sister does.  Blood type is inherited from parents like many other traits that can be displayed on a punnet square.  Depending on what the parents blood type alleles were, the brother and sister could have different blood types.  
A different number of chromosomes doesn't lead to different blood types, so D is wrong.  And A is incorrect because the number genes also does not affect blood type.  And I think the blood type genes are on the same chromosome, so B is wrong.  C is correct because blood type is inherited by alleles, and different alleles can cause different traits, such as blood types.  
 
        
             
        
        
        
One type of landform formed by wind would be sanddunes. This is the only landform I can think of formed by wind. The wind blows the sand along so that it builds up into a dune perhaps when it hits an obstacle like a small rocky spur and whole deserts can be converted into dunes.
 
        
             
        
        
        
Answer:
its  
"a heart on the run  keeps a hand on a gun  you can't trust anyone"
 
        
             
        
        
        
Plant cells are the only cells with a cell wall.