In the F2 generation of a cross, (a ratio of 9:7 would be indicative of which ty
ID: 152001 • Letter: I
Question
In the F2 generation of a cross, (a ratio of 9:7 would be indicative of which type of inheritance? a) codominance 2 genes b) independent assortment 3 genes A·.): ) lack of dominance 1 gene epistasis 2 genes epistasis,-3 genes 10. In humans, individuals heterozvgous for the M and N antigen genes have both antigens on the cell surface.Tais mechani sm of inheritance is ry a) complete dominance ed: ) incomiete dominance c) epistasis co-dominance . Twin studies were performed to determine if there was a genetic cauns had Ldapeicat chcandance va iuas.otnli n eans a zvgotic a The dsease is probably caused by the environment.: for a specific ease. Monozygotic and dizygotic had identical concordance values. This means: The disease is caused by a gene or genes. 12e hen two star eyed Drosophila flies were crossed, the offs ring ke 1/3 wild type eye:2/3 Star eyed 1des. This erOSS illustrates a) incomplete dominance )polygenic inheritance c) epistasis lethalityExplanation / Answer
the answer is (d) epistasis- 2 genes,because only in this epistasis gene interaction type i.e Duplicate recessive epistasis 9:7 ratio is observed in F2 generation .the duplicate recessive epistasis is, when the recessive alleles at either of the two loci mask the expression of dominant allele at the two loci,hence it is also known as complementary epistasis.here the normal dihybrid segregation ratio of9:3:3:1 is changed to 9:7 ratio in F2 generation . answer is (d) co-dominance.here the codominance is,in which the two allele are expressed for same characteristics in the heterozygote.here the homozygotes express either on M or N allele ,and the heterozygotes express both of them equally on the cell surface .this is one of the example of co-dominance.