Answer:
20 ( B )
Explanation:
Given data:
a and b are 10 map units apart
b and c are 20 map units apart
a and c = 30 map units apart
<em>condition </em>; Triple heterozygote testcrossed 
number of progeny = 1000 
<u>Determine the number of double crossover result </u>
P( crossover between a and b ) = 10/100 = 0.1 
P( crossover between b and c ) = 20/100 = 0.2 
p( double crossover ) = 0.1 * 0.2 = 0.02 
hence number of double crossovers = number of progeny * 0.02 
                                                               = 1000 * 0.02 = 20 
 
        
             
        
        
        
<span>A hydrophillic amino acid will have it's functional group positioned where the water is. Generally this will be outside of the polypeptide, and the amino acid will interact with polar entities, this will include other amino acids that match it's polarity.</span>
        
             
        
        
        
Through a sequence of steps called the immune response<span>, the </span>immune system<span>attacks these </span>pathogens<span>. ... This is the </span>immune system<span>. Cells. The cells involved are white blood cells (leukocytes), which seek out and destroy disease-causing organisms or substances</span>
        
             
        
        
        
The answer to this question is D
.