Final answer:
The incorrect characteristic of type 1 diabetes mellitus is that it most commonly arises in adulthood; it tends to develop in children or young adults.
Step-by-step explanation:
The characteristic of type 1 diabetes mellitus that is not correct is: a. Arises most commonly in adulthood.
Type 1 diabetes mellitus, often referred to as juvenile diabetes, mostly develops in childhood or adolescence. This contrasts with type 2 diabetes, which is more prevalent and tends to appear in adulthood. Type 1 diabetes is an autoimmune disorder, which means the immune system mistakenly attacks the insulin-producing beta cells in the pancreas.
There is indeed a genetic link to type 1 diabetes, suggesting that some individuals have a higher predisposition to the disease. Additionally, factors like viruses can influence the development of type 1 diabetes, either by triggering the autoimmune response or by directly infecting pancreatic beta cells. Finally, those with type 1 diabetes are prone to ketosis, a state resulting from the absence of insulin to facilitate glucose uptake by cells, leading to the use of fats for energy and the production of ketones.