In Pisum sativum, yellow seeds are dominant over green seeds. Round seeds are dominant over wrinkled seeds. If a true breeding Round green seeded plant is crossed with wrinkled and yellow seeded true-breeding plant, the phenotype of ${\mathrm{F}}_1$ hybrids is 

When a dihybrid cross between true breeding Round and green seeded plant is crossed with wrinkled and yellow seeded plant, all the ${\mathrm{F}}_1$ plants resemble neither of the parents but show different phenotype Round and yellow seeds because Round is dominant over wrinkled and yellow is dominant over green