Question

Heterozygous round yellow seeded plants are self crossed. Round green offspring shall be represented by genotype ________________.

• A. RrYy, RrYY, RRYy
• B. Rryy, RRyy, rryy
• C. rrYy, rrYY
• D. Rryy, RRyy
• E. RrYy, rryy, Rryy.

Answer 1

The correct option is D Rryy, RRyy

Heterozygous round yellow seeded plants are self crossed. Round green offspring will be represented by genotype. Rryy, RRyy. The genotypic symbols used are: Y for dominant yellow seeds, y for recessive green, R for round shaped seeds and r for wrinkled seeds. Therefore the genotype of the parents are RRYY and rryy. They are crossed to produce heterozygous RrYy. When this is self crossed, $3/4^{th}$ of $F_2$ generation has yellow seeds, $1/4^{th}$ had green seeds in a $3:1$ ratio. It is seen also in round and wrinkled seed shape.

Gametes RY rY Ry ry

RY RRYY RrYY RRYy RrYy

rY RrYY rrYY RrYy rrYy

Ry RRYy RrYy RRyy Rryy

ry RrYy rrYy Rryy rryy

Hence the round green offspring will be of RRyy & Rryy genotype.