What is the term for a chart showing the presence or absence of a trait according to family relationships?

• A. Pedigree
• B. Nondisjunction
• C. Restriction Enzyme
• D. Gel Electrophoresis

Answer: (A)

Understanding how traits appear across generations in a family is being tested. This chart is a pedigree. It tracks who has or does not have a trait by linking individuals through their parental relationships across generations, using symbols where usually a square is male, a circle is female, and shading indicates the trait is present. Pedigrees help scientists infer inheritance patterns—whether a trait is autosomal or sex-linked, dominant or recessive, and how it tends to appear in offspring.

The other terms refer to different concepts: a nondisjunction is an error in chromosome separation during cell division; a restriction enzyme is a tool that cuts DNA at specific sequences; gel electrophoresis is a lab technique that separates DNA fragments by size. None of these describe a family-trait chart, which is specifically a pedigree.