When crossbred pea plants are self-pollinated, what ratio do the offspring show?

The offspring ratio resulting from self-pollination of crossbred pea plants typically reflects Mendelian inheritance patterns. In this scenario, if you consider a cross between two heterozygous tall plants (where tall is dominant over short), the parental genotype can be represented as Tt (with T being tall and t being short).

When these plants are self-pollinated (Tt x Tt), the resulting genotypes in the offspring can be determined using a Punnett square. The combinations from this cross would yield:

• TT (homozygous tall),

• Tt (heterozygous tall),

• Tt (heterozygous tall),

• tt (homozygous short).

From these combinations, the phenotype ratios emerge as follows:

• 3 offspring exhibit the tall phenotype (TT and Tt),

• 1 offspring exhibits the short phenotype (tt).

This gives a classic ratio of three tall to one short, confirming that the majority of the offspring will show the dominant trait of tallness while the recessive trait of shortness will appear in a quarter of the total offspring. Therefore, the correct ratio when crossbred pea plants are self-pollinated is three tall to one short.

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