Mendel & The Gene Index Flashcards
P Generation
1st gen (true-breeding parents)
F1 Generation
Offspring of P
F2 Generation
Offspring of F1
__ alleles for every trait from each parent
Two
Allele
Alternate versions of a gene (a letter)
Law of Segregation
Only one of two alleles can be given to offspring
Homozygous
2 same alleles (PP or pp)
Heterozygous
2 different alleles (Pp)
Phenotype
Physical traits based on genotype
Genotype
Genetic make-up from 2 alleles
Punnett square
Device for predicting offspring from a cross
Monohybrid cross
2x2
Dihybrid cross
4x4
Trihybrid cross
8x8
Testcross
Used to determine if the dominant trait is unknown (homozygous or heterozygous) by crossing with recessive alleles (pp)
Law of independent assortment
Each pair of alleles segregates independently during gamete formation
Eg. color is separate from shape
Complete dominance
Heterozygote & homozygote for dominant allele are indistinguishable (YY or Yy = yellow)
Incomplete dominance
Combined appearance of parents (red x white = pink)
Codominance
Phenotype of both alleles is expressed (red x white = reed + white)
Multiple alleles
gene has 2+ alleles (ex: blood type)
Type A
IᴬIᴬ or Iᴬi
Type B
IᴮIᴮ or Iᴮi
Type AB
IᴬIᴮ
Type O
ii
Universal donor
O-
Universal acceptor
AB+
Polygenic Inheritance
effect of 2+ genes acting upon one phenotypic character
Pedigree
Diagram that shows relationship btw. parents/offspring across 2+ generations
Pleiotropy
One gene affects multiple phenotypic characters
Epistasis
Phenotypic expression of one gene affects expression of another gene
