Answer:
A 4-column Punnett square has 4 rows. The columns are labeled Upper R Upper Y, Upper R Upper Y, r Upper Y, r Upper Y. The rows are labeled Upper R Upper Y, Upper R y, Upper R Upper Y, Upper R y
Explanation:
This question involves a two distinct genes coding for seed shape and seed colour respectively. According to the question, round seeds (R) and yellow seed color (Y) are dominant to wrinkled seeds (r) and green seed color (y).
In a cross between a RRYy × RrYY parent, the following allelic combinations of gametes are produced by each parent:
RRYy- RY, Ry, RY and Ry
RrYY- RY, RY, rY and rY
A punnet square, which is a square-shaped representation of a genetic cross is used. The four possible gametes of each parent are placed on the columns and rows of the punnet square. The gametes of parent RRYy i.e. RY, Ry, RY and Ry are labeled on the rows of the punnet square while the possible gametes of parent RrYY i.e. RY, RY, rY and rY are labeled on the columns of the punnet square. (See attached image)
Hence, the correct answer is a 4-column Punnett square has 4 rows. The columns are labeled Upper R Upper Y, Upper R Upper Y, r Upper Y, r Upper Y. The rows are labeled Upper R Upper Y, Upper R y, Upper R Upper Y, Upper R y
