Enetics & Epigenetics Short Writing Assignment

For thousands of years, people have often believed that physical traits, behavioral characteristics and mental illness could be influenced by heredity, or by vagaries of the environment. For example, height has both a hereditary component as well as being influenced by factors such as nutrition. Molecular technologies allow identification of specific genes that contribute to behavioral traits and neurobiological processes, and how environmental circumstances influence genomic expression.

Please answer the following questions on a maximum of two double spaced pages.

Based on your readings of Higgins and Canli and lecture materials, answer each of the following questions. Please use complete sentences. Be concise. If you use an example outside of class materials, please indicate the source.

1. Single gene production of a clinical disorder (3 points). Some genetic mutations produce a very high risk of a specific disorder in humans. Describe one such disorder, and what is known regarding the biological mechanism.


2. Environmental influence of a biological system (6 points). Sexual and physical abuse in childhood can produce enduring changes in a person s response to subsequent stress. Conversely, children with nurturing caregivers and environments may be at lower risk for mental illness as adults. Describe possible mechanisms for these relationships based on your reading of Higgins.


3. Interaction of gene and environmental stress (6 points). Canli focuses on the role of the short and long versions of the serotonin transporter gene on behavior and mental illness. Briefly describe the relationships between different versions of the serotonin transporter gene and depression, personality characteristics, and brain activity. What is thought to be the biological basis for these relationships?