46 terms

Chapter 9: Patterns of Inheritance

STUDY
PLAY
ABO blood groups
multiple alleles and codominance
achondroplasia
autosomal dominant genetic disorder
alleles
different forms of the same gene
carrier
has the recessive allele that is masked by the dominant allele, does not show the trait
character
trait
chromosome theory of inheritance
genes are located on chromosomes, crossing over occurs between chromosomes
codominant
both alleles are equally expresses AB Blood
cross
mating to things together
cystic fibrosis (CF)
autosomal recessive genetic disorder, affects many Americans up European descent
dihybrid cross
independent assortment of two traits with hybrid allele forms, Smooth Yellow Pea Plants, Verus wrinkled green pea plants
dominant allele
form that masks the other allele
F1 generation
the results of two purebred parents (TT x tt) all Ttgeneration
F2 generation
the results of two hybrid parents (Tt x Tt)
genetics
study of inheritance
genotype
the specific allele combinations for a trait
hemophilia
polygenic inheritance -- has a range of expression and is controlled by more than one gene
heredity
study of genetics and how information is passed from one generation to the next
heterozygous
hybrid (Tt)
homozygous
purebred (TT or tt)
Huntington's 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.
hybrid
An organism that has two different alleles for a trait
hypercholesterolemia
An excessive amount of cholesterol in the blood
inbreeding
Continued breeding of individuals with similar characteristics
incomplete dominance
A pattern of inheritance in which two alleles, inherited from the parents, are neither dominant nor recessive. The resulting offspring have a phenotype that is a blending of the parental traits.
law of independent assortment
Each member of a pair of homologous chromosomes separates independently of the members of other pairs so the results are random
law of segregation
Mendel's law that states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete
linkage map
A genetic map based on the frequencies of recombination between markers during crossing over of homologous chromosomes.
linked genes
Genes located on the same chromosome that tend to be inherited together in genetic crosses
locus
A specific place along the length of a chromosome where a given gene is located.
monohybrid cross
A cross between individuals that involves one pair of contrasting traits
pedigree
A diagram that shows the occurrence of a genetic trait in several generations of a family
P generation
Parental generation, the first two individuals that mate in a genetic cross
phenotype
An organism's physical appearance, or visible traits.
pleiotropy
A single gene having multiple effects on an individuals phenotype
polygenic inheritance
combined effect of two or more genes on a single character
Punnett square
A chart that shows all the possible combinations of alleles that can result from a genetic cross
recessive allele
An allele that is masked when a dominant allele is present
recombination
(genetics) a combining of genes or characters different from what they were in the parents
frequency
How often
red-green colorblindness
A category of common, sex-linked human disorders involving several genes on the X chromosome; characterized by a malfunction of light-sensitive cells in the eyes; affects mostly males but also homozygous females.
rule of multiplication
A statistical rule stating that the probability of two independent events occuring together is the product of their individual probabilities.
sex-linked gene
gene located on the X or Y chromosome
sickle-cell disease
A human genetic disease caused by a recessive allele that results in the substitution of a single amino acid in the hemoglobin protein; characterized by deformed red blood cells that can lead to numerous symptoms.
testcross
a cross between an organism whose genotype for a certain trait is unknown and an organism that is homozygous recessive for that trait so the unknown genotype can be determined from that of the offspring
trait
A characteristic that an organism can pass on to its offspring through its genes.
wild-type traits
Traits most commonly found in nature