A homozygous round-yellow pea plant (RRYY) is crossed with a homozygous wrinkled-green plant (rryy). What is the phenotype of all the F1 offspring?

1. The F1 genotype is RrYy for every plant. 2. Round (R) is dominant over wrinkled (r), so the seed is round. 3. Yellow (Y) is dominant over green (y), so the seed is yellow. 4. Hence all F1 seeds are round and yellow, option C. 5. Wrinkled and green appear only in F2 when recessive alleles pair up, which rules out option A. _Source: Samacheer Kalvi (TN SCERT) Class 10 Science, Unit 18 Genetics "Dihybrid Cross", p.271_