Ch. 3 Mendel Flashcards
pure-breeding plants are
homozygous for a trait
Monohybrid cross
a cross between individuals that are homozygous for different alleles at the same locus (ex. AA x aa)
What is the first generation of a cross called?
The P generation
F1
the offspring of the parents in the P generation in a genetic cross
In a monohybrid cross, the F1 gen are…
all heterozygous
What are the pheno/genotypic ratios of F2 (monohybrid)
3:1 pheno
1:2:1 geno
law of segregation
the two alleles separate when gametes are formed and one allele goes into each gamete
The traits that appeared unchanged in the F1 heterozygous offspring (Mendel’s monohybrid pea cross)
dominant
The traits that disappears in the F1 heterozygous offspring
recessive
Indepentant assortment
alleles at different loci separate independently
what rule would you use: the probability of two or more independent events occurring together is calcuated by _____ their independent probabilities
multiplication rule
Dihybrid crosses reveal…
the principle of independent assortment
Dihybrid crosses
pure breeding plants for two characters (homozygous) (AABB x aabb)
What is the phenotypic ratio of a dihybrid cross (in F2)
9:3:3:1
Testcross
one individual of unknown genotype is crossed with another individual with a homozygous recessive genotype (reveals the genotype of the first individual)
