Chapter 9 Flashcards
Genetically determined classes of human blood that are based on the presence or absence of carbohydrates A and B on the surface of red blood cells. The ABO blood group phenotypes, also called blood types, are A, B, AB, and O.
ABO Blood Groups.
A form of human dwarfism caused by a single dominant allele; the homozygous condition is lethal.
Achondroplasia.
An alternative version of a gene.
Allele.
A technique for diagnosing genetic defects while a fetus is in the uterus. A sample of amniotic fluid, obtained by a needle inserted into the amnion, is analyzed for telltale chemicals and defective fetal cells.
Amniocentesis.
An individual who is heterozygous for a recessively inherited disorder and who therefore does not show symptoms of that disorder but who may pass on the recessive allele to offspring.
Carrier.
A heritable feature that varies among individuals within a population, such as flower color in pea plants.
Character.
A technique for diagnosing genetic defects while the fetus is in an early development stage within the uterus. A small sample of the fetal portion of the placenta is removed and analyzed.
Chorionic Villus Sampling (CVS).
A basic principle in biology stating that genes are located on chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns.
Chromosome Theory of Inheritance.
Inheritance pattern in which a heterozygote expresses the distinct trait of both alleles.
Codominant.
A type of inheritance in which the phenotypes of the heterozygote and dominant homozygote are indistinguishable.
Complete Dominance.
A mating of two sexually reproducing individuals; often used to describe a genetics experiment involving a controlled mating.
Cross.
The fusion of sperm and egg derived from two different individuals.
Cross-Fertilization.
A genetic disease that occurs in people with two copies of a certain recessive allele; characterized by an excessive secretion of mucus and vulnerability to infection; fatal if untreated.
Cystic Fibrosis.
An experimental mating of individuals differing at two genetic loci.
Dihybrid Cross.
The allele that determines the phenotype of a gene when the individual is heterozygous for that gene.
Dominant Allele.
A human genetic disease caused by a sex-linked recessive allele; characterized by progressive weakening and a loss of muscle tissue.
Duchenne Muscular Dystrophy.
The offspring of two parental (P generation) individuals; F1 stands for first filial.
F1 Generation
The offspring of the F1 generation; F2 stands for second filial.
F2 Generation
The genetic makeup of an organism.
Genotype.
A human genetic disease caused by a sex-linked recessive allele; characterized by excessive bleeding following injury.
Hemophilia.
Having two different alleles for a given gene.
Heterozygous.
Having two identical alleles for a given gene.
Homozygous.
A human genetic disease caused by a dominant allele; characterized by uncontrollable body movements and degeneration of the nervous system; usually fatal 10-20 years after the onset of symptoms.
Huntington’s Disease.
The offspring of parents of two different species or of two different varieties of one species; the offspring of two parents that differ in one or more inherited traits; an individual that is heterozygous for one or more pairs of genes.
Hybrid.
