a dihybrid cross is created from plants that are heterozygous for both round seeds and yellow seed color…

a dihybrid cross is created from plants that are heterozygous for both round seeds and yellow seed color. what is the ratio of offspring that have round seeds and yellow seed color? 1:16 3:16 9:16 16:16

a dihybrid cross is created from plants that are heterozygous for both round seeds and yellow seed color. what is the ratio of offspring that have round seeds and yellow seed color? 1:16 3:16 9:16 16:16

Answer

Explanation:

Step1: Determine the genotypes of parents

Let ( R ) represent the allele for round seeds (dominant) and ( r ) for wrinkled seeds (recessive). Let ( Y ) represent the allele for yellow seeds (dominant) and ( y ) for green seeds (recessive). The parents are heterozygous for both traits, so their genotype is ( RrYy ).

Step2: Use Punnett square or probability rules

For the seed - shape trait (( Rr\times Rr )): The probability of getting round seeds (( R - )) is ( P(R -)=\frac{3}{4}) (since ( RR:Rr:rr = 1:2:1)). For the seed - color trait (( Yy\times Yy )): The probability of getting yellow seeds (( Y - )) is ( P(Y -)=\frac{3}{4}) (since ( YY:Yy:yy=1:2:1)).

Step3: Calculate the probability of the combined trait

Using the multiplication rule for independent events (since the two traits assort independently according to Mendel's law of independent assortment), the probability of having round and yellow seeds is ( P(R - \text{and }Y -)=P(R -)\times P(Y -)). Substitute the values: ( P=\frac{3}{4}\times\frac{3}{4}=\frac{9}{16}).

Answer:

C. ( 9:16 )