A cardiac researcher is trying to determine if a pattern of very high blood cholesterol is genetic in a group of Pennsylvania Dutch. Therefore, the scientist looks through years of medical records, plus patterns of marriage through several generations. The investigator is doing a type of hereditary research called .

Pedigree analysis

Explanation:

Pedigree analysis is a type of research used to study gene inheritance in humans. It is used to interpret genetic information or trait patterns displayed in a family tree. Pedigree analysis tries to analyze and determine the absence or the presence of a trait in relation to family members.

When a pedigree is done it  shows the family history of a trait, hence can reveal, what chromosome the trait is linked to, family genotypes, dominant or recessive traits and phenotype probabilities in unborn children.

Therefore, from the question, the investigator is doing a type of hereditary research called pedigree analysis.

his research revealed two genetically different groups of prokaryotes, which justified splitting kingdom monera into two kingdoms. the genetic and cellular differences were so great, that these two kingdoms were eventually placed into different domains in the current three-domain system.