Table of Contents
What is the expected phenotypic ratio for the cross YYRr X YYRr?
That is, we expect a characteristic 1:2:1:2:4:2:1:2:1 ratio of the nine possible genotypes. These nine genotypes can be grouped into four phenotypes, for example 1 YYRR + 2 YYRr + 2 YyRR + 4 YyRr = 9Y-R- round, yellow peas. The ratio of these phenotypes is of course 9:3:3:1.
What is the phenotypic and genotypic ratio of this cross in F2 generation?
F2 generation has a phenotypic and genotypic ratio of 1:2:1.
How do you find the expected phenotypic ratio?
Write the amount of homozygous dominant (AA) and heterozygous (Aa) squares as one phenotypic group. Count the amount of homozygous recessive (aa) squares as another group. Write the result as a ratio of the two groups. A count of 3 from one group and 1 from the other would give a ratio of 3:1.
Is YyRr homozygous or heterozygous?
Therefore, YY is the homozygous dominant genotype (2 Y alleles). The phenotype of this genotype is yellow seed color. Yy is the heterozygous genotype (one dominant allele, one recessive allele)….Mendelian genetics review.
female\male | yr |
---|---|
YR | YyRr |
What are the phenotypes of the F2 generation?
In the resulting F2 generation, 3/4 showed the dominant phenotype, and 1/4 showed the recessive phenotype. For example, when a round seed line was crossed to a wrinkled seed line, the F1 generation was all round, and the F2 generation showed a phenotypic ratio of 3 round : 1 wrinkled.
What is the genotype of the F2 generation?
In F2 generation genotypic ratio will be 1:2:1. , i.e. 1 homozygous tall: 2 heterozygous tall: 1 homozygous dwarf. In dihybrid cross two traits are considered together. All plants of F1 generation in this cross will have similar genotype, i.e. all are heterozygous tall and heterozygous red (TtRr ).
What is the phenotype of the F2 generation?