Which method uses family history to study inheritance patterns in humans?

• A. observing eggs under a microscope
• B. pedigree analysis
• C. fertilizing human eggs in a glass dish
• D. listing the genetic characteristics of individual humans

Answer: (B)

Pedigree analysis uses family history to study how traits pass through generations in humans. By drawing a family tree and marking who shows the trait, you can see patterns that reveal whether a trait is autosomal or sex-linked and whether it behaves as dominant or recessive. For example, if an affected person appears in every generation and passes the trait to about half of their children, that suggests an autosomal dominant pattern. If the trait can skip generations and appears only when both parents carry it, that points to autosomal recessive inheritance. X-linked recessive traits often affect more males than females and can skip generations through carrier mothers. This method is especially useful in humans because we can’t perform controlled crosses, so we rely on observing how traits run in families. Other options don’t track inheritance across generations: observing eggs under a microscope looks at cell structures, fertilizing human eggs in a glass dish is a reproductive technique, and listing genetic traits of individuals focuses on one person rather than how traits are transmitted through a family.