Additional Punnette Squares

Genetic Disorders Sickle Cell Anemia – autosomal recessive (red blood cells are sickle-shaped and oxygen is not carried to cells) Cystic Fibrosis – autosomal recessive (production of thick sticky mucus – affects lung) Huntington’s Disease – autosomal dominant (neurodegenerative disorder – nerve cells start to degenerate) Hemophilia – sex linked recessive (rare bleeding disorder – blood does not clot properly)

Tay Sachs– autosomal recessive (destroys nerve cells in the brain and spinal cord) Phenylketonuria (PKU)– autosomal recessive (causes intellectual and developmental disabilities because body cannot break down the amino acid - phenylalanine) Colorblindness– sex-linked recessive (a deficiency of color vision; have difficulty in distinguishing certain colors)

Genetic Disorders: Are the harmful effects produced by inherited mutations. Mutations: *are changes in genetic material *occurs when a gene is damaged, copied incorrectly, or a faulty protein was made

Genetic Counseling – is a form of medical guidance that informs people about genetic problems that could affect them or their offspring Genetic Therapy – allows scientists to correct certain recessive genetic disorders by replacing defective genes with copies of healthy ones

Sickle Cell Anemia Sickle cell anemia is an autosomal recessive disorder. Jane is normal and does not carry the gene whereas here husband does have the disease. What percentage of their children will have sickle cell anemia? _____% Be carriers of sickle cell? ______ % 100 S S s Ss Ss Ss Ss

Huntington’s is a dominant disorder. Suppose that a man with two children, aged 15 and 17, develops Huntington’s disease at age 50. The man is heterozygous and his wife does not have the disease. What are the chances that the children will have this disease? _____% 50 H h When a disorder is autosomal dominant, can there be any carriers? h Hh hh No !! Hh hh

Tay Sachs is autosomal recessive. Kim is heterozygous for Tay Sachs and Lee does not have the disorder. What are the odds that their first child will be a carrier of Tay Sachs? ______% What are the chances the child will have Tay Sachs? _____ % 50 T t T TT Tt TT Tt

Phenylketonuria (PKU) is autosomal recessive. Frank has PKU. His wife, Amanda, is a carrier. What are the chances that their children will have PKU? ____ % Not have PKU? _____% Be a carrier of PKU? ______% 50 50 50 p p P Pp Pp pp pp

Cystic Fibrosis is an autosomal recessive disease. Suppose that a man with a family history of CF marries a woman with no history of the disease. The woman has no genes for CF while the man is a carrier (heterozygous) and does not have the disease. If these people become parents, what are the chances that their children will have CF? 0% C C C c CC CC Cc Cc