Is it multiple choice or do you just figure out 
        
             
        
        
        
It's Out Of C Or D Because It Explains It
        
                    
             
        
        
        
Answer:
C. An approximately three-to-one ratio of black to brown coated mice in F2 is accounted for by the black allele being dominant over the brown allele
Explanation:
Assuming the black genotype is BB and the brown genotype is bb.
At F1:
                  BB   x   bb = All Bb (black)
At F2:
                   Bb   x   Bb = BB (black), 2Bb (Black), bb (brown)
Th ratio of black to brown is 3:1
961 black : 317 brown is approximately 3:1.
Hence, the correct option is C. 
<em>An approximately three-to-one ratio of black to brown coated mice in F2 is accounted for by the black allele being dominant over the brown allele</em>
 
        
             
        
        
        
Ok, so when a horse (with 64 chromosomes) is crossed with a donkey(that has 62 chromosomes), each parent give its child half of its chromosomes. [64/2=32] [62/2=31]. So the mule gets 31 pairs of chromosomes plus 32 pairs of chromosomes. That equals 63 total chromosomes. In order to be a parent, it must give <span>half of its chromosomes to its child. [63/2=31.5] You can't have half a chromosome, so the mule is a sterile organism. Let me know if you have questions.</span>