Chapter 14 Flashcards
An observable heritable feature.
Character
Any detectable variant in a genetic character.
Trait
Referring to plants that produce offspring of the same variety when they self-pollinate.
True-Breeding
In genetics, the mating, or crossing, of two true-breeding varieties.
Hybridization
Any of the alternative versions of a gene that produce distinguishable phenotypic effects.
Alleles
Mendel’s first law, stating that the two alleles in a pair segregate (separate) into different gametes during gamete formation.
Law of Segregation
Mendel’s second law, stating that each pair of alleles segregates, or assorts, independently of each other pair during gamete formation; applies when genes for two characters are located on different pairs of homologous chromosomes.
Law of Independent Assortment
A diagram used in the study of inheritance to show the predicted results of random fertilization in genetic crosses.
Punnett Square
An allele that is fully expressed in the phenotype of a heterozygote.
Dominant Allele
An allele whose phenotypic effect is not observed in a heterozygote.
Recessive Allele
Having two different alleles for a given gene.
Heterozygous
Having two identical alleles for a given gene.
Homozygous
The genetic makeup, or set of alleles, of an organism.
Genotype
The physical and physiological traits of an organism, which are determined by its genetic makeup.
Phenotype
The situation in which the phenotypes of the heterozygote and dominant homozygote are indistinguishable.
Complete Dominance
The situation in which the phenotype of heterozygotes is intermediate between the phenotypes of individuals homozygous for either allele.
Incomplete Dominance
The situation in which the phenotypes of both alleles are exhibited in the heterozygote because both of the alleles affect the phenotype in separate, distinguishable ways.
Codominance
A human genetic disease caused by a recessive allele for a dysfunctional enzyme, leading to accumulation of certain lipids in the brain.
Tay Sachs Disease
A type of gene interaction in which one gene alters the phenotypic effects of another gene that is independently inherited.
Epistasis
The ability of a single gene to have multiple effects.
Pleiotropy
An additive effect of two or more genes on a single phenotypic character.
Polygenic Inheritance
Referring to a phenotypic character that is influenced by multiple genes and environmental factors.
Multifactorial
A diagram of a family tree showing the occurrence of heritable characters in parents and offspring over multiple generations.
Pedigree
In genetics, an individual who is heterozygous at a given genetic locus, with one normal allele and one recessive allele.
Carriers
A human genetic disorder caused by a recessive allele for a chloride channel protein; characterized by an excessive secretion of muss and consequent vulnerability to infection; fatal if untreated.
Cystic Fibrosis
A juan genetic disease caused by a recessive allele that results in the substitution of a single amino acid in a globin polypeptide that is part of the hemoglobin protein; characterized by deformed red blood cells (due to protein aggregation) that can lead to numerous symptoms.
Sickle Cell Disease
A human genetic disease caused by a dominant allele; characterized by uncontrollable body movements and degeneration of the nervous system; usually fatal 10 to 20 years after the onset of symptoms.
Huntington’s Disease
A technique of prenatal diagnosis in which amniotic fluid, obtained by aspiration from a needle inserted into the uterus, is analyzed to detect certain genetic and congenital defects in the fetus.
Amniocentesis
A technique of prenatal diagnosis in which a small sample of the fetal portion of the placenta is removed and analyzed to detect certain genetic and congenital defects in the fetus.
Chorionic Villus Sampling
