Question

In snapdragon plants, the allele for tallness (T) is dominant to the allele for dwarfism (t). As well, red colour is due to the (R) allele, while white is due to (r) allele. The heterozygous condition results in pink flowers. A dwarf, red snapdragon plant is crossed with a plant that is homozygous for tall and white flowers. The genotypic and phenotypic ratios for the f1 plants are? What is the mode of inheritance expressed in this cross?

Answer 1

The F1 cross between a dwarf red snapdragon (ttRR) and a tall white snapdragon (TTrr) will result in all tall pink snapdragons (TtRr), displaying a 1:0 genotypic and phenotypic ratio. Incomplete dominance is the mode of inheritance for the flower color.

Step-by-step explanation:

In the given snapdragon plants, tallness (T) is dominant over dwarfism (t), while the flower color follows a pattern of incomplete dominance, where red (R) is incompletely dominant over white (r), resulting in pink flowers for the heterozygous condition (Rr).

Considering a cross between a dwarf, red snapdragon plant (which must be ttRR) and a plant that is homozygous for tall and white flowers (which is TTrr), the F1 generation will all be TtRr (tall and pink flowers). This is because each parent contributes one allele for each gene. So the genotypic ratio for the F1 plants will be 1:0 - all of them will have the same genotype (TtRr). The phenotypic ratio will also be 1:0 as all offspring will display the same phenotype (tall and pink flowers). The mode of inheritance expressed here is incomplete dominance for the flower color.

Answer 2

TRr That is all I can get, if I am wrong I am sorry.