Answer:
He is afraid of being infected. What horrors does the narrator witness during regular walks to his brother's house? People are dying on the streets, women shrieking and crying, and people do harm to themselves and others.
Explanation:
There are three main differences between nuclear and mitochondria DNA (mtDNA): 1.) mtDNA is circular, whereas nuclear DNA is linear. (Both are double stranded) 2.) mtDNA is (generally) uni-parentally inherited, in most animals (not mussels though for example), mtDNA is passed from mother to offspring. from wiki
1. D determined
2. B pictured
