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chromosome theory of inheritance
states that (1) genes are located on chromosomes (2) the behavior of chromosomes during meiosis and fertilization accounts for inheritance patterns
a gene that is expressed when multiple alleles are present; capital letter, ex: P for purple
family tree representing occurance of genes in parents and offspring across generations) shows the history of a trait in a family and allows researchers to analyze human traits
Females must receive 1 copy from each parent (2 total) to phenotypically acquire a recessive trait and males need
only 1 recessive gene on the X chromosome to phenotypically acquire a recessive trait
(egg and sperm) carry only one allele for each inherited characteristic because allele pairs separate in the production of gametes (meiosis)
Was the first person to scientifically analyze patterns of inheritance (studied garden peas which self-fertilize)
Found that genetic characteristics followed a few simple rules and deduced the fundamental principles of genetics
Homologous chromosomes have genes at specific
loci (locations of specific genes on a chromosome) and alleles of a gene at the same locus
mating of close relatives; ↑chances of offspring being homozygous for harmful recessive traits
when the phenotype of heterozygote (Aa) is intermediate between the phenotypes of homozygotes (AA and aa)
Each pair of alleles segregates independently of the other pairs during gamete formation; the inheritance of one characteristic has no effect on the inheritance of the other
Many human characteristics result from a combination of
heredity and environment, including skin color
Mendel's principle of segregation
pairs of alleles segregate (separate) during gamete formation; the fusion of gametes at fertilization creates allele pairs again
is a cross between parent plants that differ in only one characteristic ex. flower color
is the impact of a single gene on more than one characteristic, sickle-cell disease is an example
a gene that is not expressed when multiple alleles are present; lower case letter, ex: p for white flower
Rule of multiplication
probability of a compound event is the product of the separate probabilities of the independent events.
any genes located on a sex chromosome
Were discovered during studies on fruit flies while studying eye color (gene found to be on X chromosome)
is a mating between an individual of unknown genotype (P_) and homozygous recessive individual (pp)
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