Subject
Science

Activity Overview
Some traits are biological; they are caused by genes. Other traits are not present at birth but are learned from a parent or some factor in the environment. It is not always easy to determine which category-genetics or environment-is responsible for a particular trait. In this activity students will trace one of these "undecided categories" through their ancestors. Afterwards they will try to conclude whether the characteristic was inherited or learned.

Activity Outline
Have students:
1. Choose a trait which is not clearly biological and is present in several family members, such as:

• musical ability
• an unusual intellectual interest
• shyness/introversion
• a love of acting or drama
• ability to roll up one's tongue or wiggle ears

2. Construct a family tree, beginning with your siblings and going back through at least three generations of your ancestors. Trace the trait through the generations, indicating its presence on the family tree through color-coding or some other means. Include a key.

Assessment
Have students present their family trees and discuss their findings. Students could design the family tree on the computer, using a program for word processing, publishing, or any other appropriate software.

Standards and Benchmarks
Standard 4: Understands the principles of heredity and related concepts
4. Knows that hereditary information is contained in genes (located in the chromosomes of each cell), each of which carries a single unit of information; an inherited trait of an individual can be determined by either one or many genes; and a single gene can influence more than one trait
5. Knows that the characteristics of an organism can be described in terms of a combination of traits; some traits are inherited and others result from interactions with the environment