Question

5. In garden peas, axial flower position is dominant and terminal flower position is recessive. Tall
plants are dominant to short plants. A plant that is known to be purebred for tall vine and axial
flowers is crossed with a plant having short vines bearing terminal flowers. What is the
phenotype of this offspring? Predict the kinds of offspring that would appear in the F2
Generation, using genotypic and phenotypic ratios

Answer 1

Explanation:

It's just like the mendelian dihybride cross.

Tallness=TT , shortness=tt

Axial flower=AA , terminal flower=aa

Now the purebred tall & axial flower plant genotype = TTAA

And purebred short & terminal flower plant genotype = ttaa

Answer 2

The mendelian dihybride cross

Tallness=TT , shortness=tt

Axial flower=AA , terminal flower=aa

Therefore, the purebred tall & axial flower plant genotype = TTAA

purebred short & terminal flower plant genotype = ttaa

After crossing

phenotypic ratio is tall axial : tall terminal: short axial: short terminal

                                      $\frac{9}{16}$                 $\frac{3}{16}$                  $\frac{3}{16}$                     $\frac{1}{13}$

Genotypic ratio is 1:2:1:2:4:2:1:2:1

Explanation:

1.A phenotypic ratio is a quantitative relation between phenotypes showing the number of times the frequency of one phenotype correlates with another.

2.When a researcher would like to obtain the gene expression for generations of an organism, they use the phenotypic ratio obtained from a test cross

3The genotypic ratio is the ratio depicting the different genotypes of the offspring from a test cross. It represents the pattern of offspring distribution according to genotype, which is the genetic constitution determining the phenotype of an organism.

4.A dihybrid cross describes a mating experiment between two organisms that are identically hybrid for two traits. A hybrid organism is one that is heterozygous, which means that is carries two different alleles at a particular genetic position, or locus.