Chapter 11.6

1. Chapter 11.6 Genes and the Environment AP Biology Fall 2010

2. Environment Conditions The environment contributes to variations in gene expression amoung individuals in a population

3. Himalayan Rabbit Example Fur on the extremities of Himalayan rabbits will be darker This is because the enzyme for melanin production will operate at cooler temperatures but, is sensitive to heat on the rest of the body

4. Yarrow Plant Example • Cuttings (come from the same parent plant) from Yarrow plant clones grew differently at three different altitudes • Cuttings from one plant grew tall at the lowest and the highest elevation • But a third cutting remained short at mid-elevation • Even though these plants were genetically identical, their phenotypes differed in different environments

5. Hydrangea Plant Example The colour of the floral clusters on Hydrangea will vary depending on the acidity of the soil

6. People Example Some people tolerate stress better than others Perhaps due to differences in the gene for a serotonin transporting protein Serotonin compromises response to stress

7. Review Understand that environmental factors can influence gene expression, know some examples How could this be a positive or negative factor? Would this have anything to do with the nature/nurture debate?