Ch 11 Complex Inheritance and Human Heredity Vocabulary

Ch 11 Complex Inheritance and Human Heredity Vocabulary carrier an individual who is heterozygous for a recessive disorder pedigree diagram that traces the inheritance of a particular trait through several generations Recessive Requires two recessive alleles to have disorder genetic disorders Ethnic groups sharing a common and distinctive culture, religion, language

Cystic fibrosis Recessive genetic disorder that causes excess mucus in lungs and respiratory system; common in caucasians albinism Recessive genetic disorder that occurs in people that lack the pigment melanin. Causes individuals to have white hair, pale skin, and pink eyes. melanin Pigment that causes the color in skin, hair and eyes.

Galactosemia Recessive genetic disorder that causes a problem in an enzyme that breaks down the sugar galactose; causes mental deterioration and liver and kidney problems. Tay-Sachs Recessive genetic disorder that eventually causes mental retardation disease because of a lack of an enzyme. Occurs mainly in people of Jewish descent. PKU Recessive genetic disorder that causes mental retardation due to a defective enzyme that cannot break down phenylalanine. Dominant Occur when just one dominant allele is present; hitch hikers thumb, free genetic traits hanging earlobes, and tongue rolling Dominant Disorders caused by just one dominant allele genetic disorders polydactyl Dominant disorder that causes an individual to have more than 5 fingers or toes Huntington’s Dominant inherited disorder that affects the central nervous system and Disease is fatal. Achondroplasia Dominant disorder; commonly called dwarfism incomplete the heterozygous phenotype is an intermediate phenotype between the dominance two homozygous phenotypes (ex: red, pink, white) codominance both alleles are expressed in the heterozygous phenotype (ex: in sickle cell disease; normal, sickle, normal and sickle and AB blood group) multiple alleles having more than two alleles for a specific trait. (ex: blood groups in humans, coat color in rabbits) epistasis the result of one allele hiding the effects of another allele (ex: Labrador coat color) sex the pair of chromosomes that determine an individual’s gender. (EX: chromosomes XY=male, XX=female) autosomes the other 22 pair of chromosomes that are not sex chromosomes sex-linked traits controlled by genes on the X chromosome, also called X-linked. traits polygenic phenotypic traits that arise from the interaction of multiple pairs of traits genes. (ex: skin color, height, eye color, fingerprint pattern) intermediate A go between; a mediator—a mixture of two different phenotypes in

incomplete dominance Sickle cell Changes shape of red blood cells. Causes the blood cell not to carry disease oxygen as well. Inheritance is through codominance. An individual can have normal and sickle cells in the heterozygous state. malaria Infectious disease caused by mosquitos. People with sickle cell trait have protection against catching malaria. Dosage Also known as x-inactivation; In females, who have two x chromosomes, compensation one is inactivated. One of the x chromosomes stops working in each of the females body cells Red green Trait for this disorder is carried on the x chromosome therefore; son colorblindness inherits gene from mom; rare in girls Hemophilia Trait for this disorder carried on the x chromosome; causes the delayed clotting of blood. More common in males than females telomeres protective cap on the end of chromosomes, might be involved in aging and cancer nondisjunction sister chromatids fail to separate properly during cell division monosomy having only one of a particular type of chromosome. trisomy having a set of three chromosomes of one kind

Down Chromosomal abnormality in which there are 3 copies of chromsome 21 syndrome Turner’s Chromosome abnormality on sex hormone. A female only has one copy syndrome of the x chromosome. XO Kleinfelter’s Chromosome abnormality on the sex hormone. A male has an extra syndrome copy of an X chromosome. XXY Fetal testing Used to determine the possibility of a genetic disorder by taking a sample of fetal cells.