Question

a tall plant is crossed with a dwarf plant. the offspring are all tall. if we let t represent the allele for tall and let t represent the allele for dwarfism, what are the probable geneotypes of the parents?

Answer 1

The probable genotypes for the tall plant and dwarf plant parents producing all tall offspring are likely Tt (heterozygous tall) and tt (homozygous dwarf), respectively. A Punnett square for this cross would show a 100% tall phenotypic ratio among the offspring.

Step-by-step explanation:

The probable genotypes of the parents in a cross where a tall plant is bred with a dwarf plant and all offspring are tall, can be predicted using Mendelian genetics. If we let T represent the allele for tallness and t represent the allele for dwarfism, the dominant factor (T) masks the recessive factor (t). Therefore, a tall (Tt) plant crossed with a dwarf (tt) plant will result in all tall offspring (Tt). This indicates that the tall parent is likely heterozygous (Tt) if all offspring are tall.

To further illustrate, you can use a Punnett square to predict these crosses. When a heterozygous tall pea plant (Tt) is crossed with a homozygous dwarf (tt) plant, the phenotypic ratio of the offspring will be 100% tall, since each offspring will inherit at least one dominant allele (T).