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In a species of pea plant, the gene for seed shape has two alleles. The allele for round seeds, R, is dominant to the allele for wrinkled seeds, r.
Define the term allele.
Explain the difference between a homozygous and a heterozygous pea plant for the seed-shape gene.
A round-seeded pea plant may be homozygous or heterozygous. Explain why a wrinkled-seeded plant must be homozygous.