3: Basic Principles of Heredity Flashcards
Year Mendel publishes his experiments
1866
Birthdate of Modern Genetics, “Rediscovery of Mendel’s work”
1900
The Chromosome Theory of Heredity
chromosomes are the carriers of genes
states that two alleles of a genes, on maternal and one paternal, separate in equal proportions when gametes are formed (separation of Aa into gametes)
Segregation (Mendel’s First Law)
states that alleles at different loci separate independently (Aa separates into gametes regardless of how Bb separates) i.e. genes are not linked
Independent Assortment (Mendel’s Second Law)
cross between parents that differ in a single characteristic
monohybrid cross
first generation of a cross
P (parental) generation
offspring of P generation
F1 (first filial) generation
what do monohybrid crosses reveal?
principle of segregation and concept of dominance
states that when two different alleles are present in a genotype, only the trait encoded by one of them is observed in the phenotype
concept of dominance
F1 x P cross
backcross
1st place you can determine which allele is dominant
F1 generation
form of progeny testing that reveal the genotype of an individual of dominant phenotype. always cross with a homozygous recessive (A_ x aa)
testcross
predicts probability of joint occurrence of independent events (AND)
multiplication rule
predicts probability of either occurrence of mutually exclusive events (OR)
addition rule