What does it mean when a locus is “informative” in engraftment testing?

The major histocompatibility complex (MHC) in humans is also known as:

Polymorphisms may or may not have:

Which organism is best diagnosed using molecular methods due to low culture sensitivity?

RFLP changes are due to: 

What of the following is used as a marker of gender?

Which best describes most SNPs?

Polymorphisms are useful as: 

Which of the following polymorphisms are tandem repeats of 1-8 bps?

Funduscopic examination of a 68-year-old woman finds arteriolar narrowing, flame-shaped hemorrhages, cotton-wool spots and hard waxy exudates.  Which of the following underlying diseases is she most likely to have?