how does a geneticist use pedigrees?

(a) to create genetic crosses
(b) to replicate identical strings of dna
(c) to prove that sex-linked traits are caused by codominant alleles
(d) to trace the inheritance of traits in humans

The correct answer is- (D) To trace the inheritance of traits in humans.

Pedigree is a representation of family members ( in the form of flow chart with specific symbols) that indicates a trait ( such as sickle cell anemia, which is an autonomous recessive trait) in a family and across many generations.

Pedigree analysis is done to determine genotypes, morphological form, and predict the chances of passing a trait in the next generation.

There can be different inheritance pattern for a trait ( such as dominant, recessive, autosomal, or sex-linked).

Thus, genetic counselors perform pedigree analysis in order to help families in identifying the risk of genetic disorders and are used by research scientists in determining inheritance pattern of traits in humans.