What is the expected phenotype ratio of the PPSs x Ppss cros

What is the expected phenotype ratio of the PPSs x Ppss cross described in the previous question? Write the ratio in the order of # purple smooth, # purple constricted, # white smooth, # white constricted. Use the format as in the following example: 2:2:1:0 (integers separated by colons with no spaces; be sure to type zero and not the letter O if the phenotype is expected to be absent; also the ratio must be reduced).

Solution

Answer

Allele for character for Purple is P

Allele for character for White is p

Allele for character for Smooth is S

Allele for character for constricted is s

The combination of these alleles will be

Purple smooth PPSS, PpSs

Purple constricted PPss, Ppss

White smooth                   ppSS, ppSs

White constricted             ppss

Parents P1                                        PPSs x Ppss

Gamets                                 PS PS Ps Ps Ps Ps ps ps

Cross

Ps

Ps

ps

ps

PS

PPSs

PPSs

PpSs

PpSs

PS

PPSs

PPSs

PpSs

PpSs

Ps

PPss

PPss

ppss

ppss

Ps

PPss

PPss

ppss

ppss

Number of purple and smooth will be 8

Number of purple and constricted will be 4

Number of white and smooth will be 0 (zero)

Number of white and constricted will be 4

Therefore, the phenotypic ratio of purple smooth, purple constricted, white smooth, white constricted will be 8:4:0:4