If pea plants with round and green seeds (RRyy) are crossed with pea plants having wrinkled and yellow seeds (rrYY), the seeds developed by the plants of $F_1$ generation will be :

Mendel's law of inheritance states that when two different traits are crossed, the dominant trait will be expressed in the F1 generation. In this case, the pea plants with round seeds (RR) are crossed with pea plants having wrinkled seeds (rr), and the seeds developed by the plants of F1 generation will be round. Similarly, the pea plants with green seeds (yy) are crossed with pea plants having yellow seeds (YY), and the seeds developed by the plants of F1 generation will be yellow. Therefore, the seeds developed by the plants of F1 generation will be 100% round and yellow.