Book Viewer

Short Contents | Full Contents | Other books @ NCBI

| Modern Genetic Analysis Chapter 4. The Inheritance of Genes Human Pedigree Analysis Figure 4-19. An albino. The phenotype is caused by homo-zygosity for a recessive allele, say,a/a. The dominant alleleA determines one step in the chemical synthesis of the dark pigment melanin in the cells of skin, hair, and eye retinas. In a/a individuals this step is nonfunctional, and the synthesis of melanin is blocked. (© Yves Gellie/Icône.)

© 1999 by W. H. Freeman and Company. All rights reserved.