BIO.CH 20

Alternative form of a genel alleles occur at the same locus on homologous chromosomes

Any chromosome other than the sec chromosomes

Heterozygous individual who has no apparent abormality but can pass on an allele for a recessively inherited genetic disorder

Inheritance pattern in which both alleles of a gene are equally expressed

Deficiency in one or more of the three types of cone cells responsible for color vision

A generalized, autosomal recessive disorder of infants and children in which there is widespread dysfunction of the exocrine glands

Individual that is heterozygous for two traits; shows the pheotype governed by the dominant alleles but carries the recessive alleles

Allele that exerts its pehotypic effect in the heterozygotel it masks the expression of the recessive allele

Chronic progessive disease affecting the shoulder and pelvic girdles, commencing in early childhood. Characterized by increasing weakness of the muscles, followed by atrophy and a peculiar swaying gait with the lefs kept wide apart. transmitted as X-linked trait, and affected individuals, predominantly males, rarely survive to maturity. Death is usually due to respiratory weakness or heart failure.

Inability to remove cholesterol from the bloodstream; predisposes individual to heart attack

Most common inherited form of mental retardation; results from mutation to a single gene and results in deficiency of a protein critical to brain development

Genes of an individual for a particular trait or traits; often designated by letters, for example, BB or Aa.

Genetic disorder in which the affected individual is subject to uncontrollable bleeding.

Possessing unlike alleles for a particular trait

Possessing two identical alleles, such as AA, for a particular trait

Possessing two identical alleles, such as aa, for a particular trait

Genetic disease marked by progerssive deterioration of the nervous system due to deficiency of a neurotransmitter

Inheritance pattern in which the offspring has an intermediate phenotype, as when a red-flowered plant and a white-flowered plant produce pink-flowered offspring.

Particular site where a gene is found on a chromosome. Homologous chromosomes have corresponding gene loci.

Congenital disorder of connective tissue characterized by abnormal length of the extremities

Individual that is heterozygous for one trait; shows the phenotype of the dominant allele but carries the recessive allele

Controlled by several allelic pairs; each dominant allel contributes to the phenotype in an additive and like manner

Inheritance pattern in which there are more than two alleles for a particular trait; each individual has only two fo all possible alleles

Visible expression of a genotype - for example, brown eyes or attached earlobes

Result of accumulation of phenlalanine, characterized by mental retardationg, light pigmentation, exzema, and neurologic, manifestations unless treated by a diet low in phenylalanine

Trait is controlled by several allelic pairsl each dominant allele contributes to the phenotype in an additive and like manner

Gridlike device used to calculate the expected results of simple genetic crosses

Allele that exerts its phenotypic effect only in the homozygote; its expression is masked by a dominant allele

Chromosome that determines the sec of an individual; in humans, females have two X chromosomes, and males have an X and Y chromosome.

Allele that occurs on the sex chromosomes but may control a trait that has nothing to do with the sex characteristics of an individual

Genetic Disorder in which the affected individual has sicle-shaped red blood cells subject to hemolysis

Letahl genetic disease in which the newborn has a faulty lysosomal digestive enzyme

Allel located on an X chromosome, but may control a trait that has nothing to do with the sec characteristics of an individual