The red-green color blindness is a recessive X-linked trait. The females are not affected unless both the X chromosomes have the affected allele. Mostly, the females are the carriers, and the males are affected as they have only one X chromosome. In the given pedigree, the father of Irene have the normal allele, while her mother is a carrier. However, Irene is neither a carrier nor affected. This means that she carries normal alleles on both X chromosomes. Hence, her allele combination is  .
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Answer:
Explanation:
(in an echinoderm) each of a large number of small flexible hollow appendages protruding through the ambulacra, used either for locomotion or for collecting food and operated by hydraulic pressure within the water-vascular system.
 
        
             
        
        
        
<em>Answer </em><em>is </em><em>- </em><em>D </em><em>the electron transport </em><em>chain </em><em>combined </em><em>with</em><em> </em><em>chemiosmosis </em>