Vocabulary Review Ch 12 Inheritance Patterns and Human Genetics

One of the pair of chromosomes that determine the sex of an individual Sex Chromosome

Any chromosome that is not a sex chromosome Autosome

A trait that is determined by a gene found on one of the sex chromosomes, such as the X chromosome or the Y chromosome in humans Sex-linked Trait

One of a pair of genes that tend to be inherited together Linked Gene

A diagram of gene positions on a chromosome Chromosome map

In chromosome mapping, an increment of 1 percent in the frequency of crossing-over Map unit

Mutation that occurs in an organism’s gametes Germ-cell mutation

A mutation that occurs in a body cell Somatic-cell mutation

A gene or chromosomal mutation that influences the development of an organism in such a way that the organism cannot survive Lethal mutation

The loss of a part of DNA from a chromosome Deletion

A reversal in the order of the genes, or of a chromosome segment, within a chromosome Inversion

The movement of a segment of DNA from one chromosome to another, which results in a change in the position of the segment; also the movement of soluble nutrients from one part of a plant to another Translocation

The failure of homologous chromosomes to separate during meiosis I or the failure of sister chromatids to separate during mitosis or meiosis II Nondisjunction

A mutation in which only one nucleotide or nitrogenous base in a gene is changed Point mutation

A mutation in which a nucleotide or a codon in DNA is replaced with a different nucleotide Substitution

A mutation, such as the insertion or deletion of a nucleotide in a coding sequence, that results in the misreading of the code during translation because of a change in the reading frame Frameshift mutation

A mutation in which one or more nucleotides are added to a gene Insertion mutation

A diagram that shows the occurrence of a genetic trait in several generations of a family Pedigree

In genetics, an individual who has one copy of a recessive autosomal allele that causes disease in the homozygous condition Carrier

An inherited disease or disorder that is caused by a mutation in a gene or by a chromosomal defect Genetic disorder

Describes a characteristic that is influenced by many genes Polygenic

A character such as skin color that is influenced strongly by both genes and the environment Complex character

More than two alleles (versions of the gene) for a genetic trait Multiple allele

A condition in which both alleles for a gene are fully expressed Codominance

A condition in which a trait in an individual is intermediate between the phenotype of the individual’s two parents because the dominant allele is unable to express itself fully Incomplete dominance

An autosomal trait that is influenced by the presence of male or female sex hormones Sex-influenced trait

A rare hereditary disease of the brain characterized by involuntary movements of the limbs or face, decreasing mental abilities, and eventual death Huntington’s disease

A procedure used in fetal diagnosis in which amniotic fluid is removed from the uterus of the pregnant woman Amniocentesis

A procedure in which the chorionic villi are analyzed to diagnose fetal genotypes Chorionic villi sampling

The process of testing and informing potential parents about their genetic makeup and the likelihood that they will have offspring with genetic defects or hereditary diseases Genetic counseling

A technique that places a gene into a cell to correct a hereditary disease or to improve the genome Gene therapy