Well all cells in a multicellular organism have the same exact DNA (except for sex cells). But what makes each type of cell different physically and functionally is the genes that are expressed in those cells.So for like example a different section of the DNA molecule is expressed in a nerve cell than a skin cell.
The kingdom of multicellular organisms that use photosynthesis to create their food are called Plantae.
This would be a recessive disease.
Father is dd
Mother is Dd (has to be because one child has the disease)
Parents cross is dd x Dd which gives rise to Dd (0.5) and dd (0.5). Each time they have a child they have a 50% chance of the child having the disease. In their case, only one of their 3 children is dd. The others though are carriers!