Some of the most common diseases are infections caused by bacteria, such as Campylobacter, Salmonella, Shigella, E. coli O157:H7, Listeria, botulism, and norovirus.
A genotype is the actual genetic coding for an organism. A phenotype is the physical appearance. For example, let's say BB or Bb is the coding for black hair. BB/Bb is the genotype, and the black hair is the phenotype.
The genotype is the genetic constitution of a cell, an organism, or an individual (i.e. the specific allele makeup of the individual) usually with reference to a specific character under consideration [1][2].