Answer:
1/2
Explanation:
Let's assume that the allele "p" is responsible for PKU in the homozygous state. According to the given information, both the parents are unaffected by the disorder but have an affected child. This means that both the parents carry at least one copy of the recessive allele responsible for the disease. Therefore, the genotype of each of the parents is Pp. A cross between Pp and Pp would produce progeny in following ratio=
Pp x Pp = 1/4 PP: 1/2/ Pp: 1/4 pp
Therefore, the probability that their next child will carry just one recessive allele is 1/2.  
 
        
             
        
        
        
Answer:
C) It involves interactions between biotic and
abiotic factors.
Explanation:
Ecosystems need energy imput, need both consumers and producers, and can exist on land, lakes, rivers and oceans.
 
        
             
        
        
        
In a dominant cross, the chance of the dominant phenotype showing up in one of the offspring is 3/4, since the dominant genes are being shown here. 
        
             
        
        
        
When you touch a hot plate, the transfer of heat from the plate to your hand is called Conduction.
Conduction is the answer you are looking for. 
        
                    
             
        
        
        
Answer:
B
Explanation:
because they are moving at the same direction