Chapter 3 Genetics, Conception, Fetal Development, and Reproductive Technology ! Genetics " study of heredity ! Genomics " addresses all genes and their interrelationships in order to identify their combined influence on growth and development of the organism o Providing better methods for preventing disease and abnormalities, diagnosing diseases, predicting health risks, personalizing treatment plans ! 30,000 genes in the human genome (organism’s complete set of DNA) ! 46 chromosomes; 22 homologous pairs of chromosomes and one pair of sex chromosomes ! genotype " person’s genetic makeup ! phenotype " how genes are outwardly expressed (eye color, hair color, height) ! recessive genetic disorders " sickle cell anemia, cystic fibrosis, thalassemia, Tay-Sachs disease ! carrier testing " identify individuals who carry one copy of a gene mutation that, when present in two copies causes a genetic disorder; used when there is a family history of genetic disorder ! preimplantation testing/preimplantation genetic diagnosis " used to detect genetic changes in embryos that are created using assisted reproductive techniques ! prenatal testing " early detection of genetic disorders ! risks for conceiving child with genetic disorder " maternal age older than 35, man/woman who has genetic disorder; family history of genetic disorder, history of previous pregnancy resulting in a genetic disorder or newborn abnormalities ! refer to support group whether they wish to terminate/continue with pregnancy ! sickle cell anemia o most common of African ancestry o sickle-cell hemoglobin forms rigid crystals that distort and disrupt RBCs; oxygen-carrying capacity of blood is diminished