Question

make a hypothesis: what will the offspring of two f₁ \yyrr\ plants will look like? (select all that apply)
yellow, round seeds
yellow, wrinkled seeds
green, wrinkled seeds
green, round seeds

Explanation:

When two \( F_1 \) plants with genotype \( YyRr \) (dihybrid) are crossed, we use the principle of independent assortment and the Punnett square for dihybrid cross. The alleles for seed color (\( Y \) - yellow, dominant; \( y \) - green, recessive) and seed shape (\( R \) - round, dominant; \( r \) - wrinkled, recessive) assort independently. The possible gametes from each \( YyRr \) plant are \( YR \), \( Yr \), \( yR \), \( yr \). When we cross these, the phenotypic ratio of the offspring (in a typical Mendelian dihybrid cross) is \( 9:3:3:1 \) for yellow - round (\( Y\_R\_ \)) : yellow - wrinkled (\( Y\_rr \)) : green - round (\( yyR\_ \)) : green - wrinkled (\( yyrr \)) respectively. So all four phenotypes (yellow, round seeds; yellow, wrinkled seeds; green, wrinkled seeds; green, round seeds) are possible in the offspring.

Answer:

A. Yellow, round seeds
B. Yellow, wrinkled seeds
C. Green, wrinkled seeds
D. Green, round seeds