Question

in a pedigree chart, what does a vertical line connecting to a horizontal line indicate? a sibling relationship; a marriage; parent - child relationship; a genetic trait

Explanation:

In a pedigree chart, a horizontal line between two individuals represents a marriage. A vertical line connecting to this horizontal line leads to the offspring, indicating the parent - child relationship. Sibling relationships are shown by lines branching from a common point (the parents' line). A genetic trait is represented by symbols (like filled or unfilled shapes) for each individual, not by the line connections described.

Answer:

Parent - child relationship