Ch. 14 Vocab Flashcards
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 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 pressed in the phenotype of a heterozygous
dominant allele
an allele whose phenotype 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 the 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 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; seizures, blindness, and degeneration of motor and mental performance usually manifest a few months after birth, followed by death within a few years
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 mucus and consequent vulnerability to infection; fatal if untreated
cystic fibrosis
a human 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
sickle cell disease
a human genetic disorder 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
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
an observable heritable feature
character
