Epistasis And Gene Interaction Flashcards
What is a dihybrid cross
Parents differ in two characters
What causes the 9:3:3:1 ratio
Independent assortment - no interaction
What is the first law
Law of segregation - during gamete formation, each member of allelic pair separates from each other to form genetic constitution of gamete
What is the second law
Independent assortment - each pair of alleles segregates independently of the other pairs of alleles during gamete formation
What are complementary genes
Genes which are present on different genetic loci but interact with each other to express a new phenotype
E.g. comb shape in poultry
What is epistasis
Expression of gene suppressed by action of a gene or genotype at another chromosome
What is a hypostatic trait
Phenotype being suppressed
What does epistasis do to the phenotype ratio
Causes different phenotype ratios
What does epistasis do to genotype ratio
Genotype ratio is unchanged
What is the recessive epistasis ratio
9:3:4
What is the dominant epistasis ratio
12:3:1
What is the epistatic gene locus
Locus with gene that affects another gene by masking it
What is the hypostatic gene locus
Locus with gene that is being masked
