In peas, the dominant seed shape is round and the recessive is wrinkled(w). The
ID: 15852 • Letter: I
Question
In peas, the dominant seed shape is round and the recessive is wrinkled(w). The dominant trait for pod color is green and recessive is yellow (y). A plant with round seeds and green pods that i heterozygous only for the color trait is crossed with a plant that has wrinkled seeds and yellow pods, and the resulting F1 progeny are selfed(self fertilized).Write out the P1 genotpes and the F1 and F2 genotypic and phenotypic ratios.
What proportion of the plants with green pods and round seeds from the F2 generation would you expect to be true breeding(i.e. produce only plants with green pods and round seeds)?
Explanation / Answer
In peas, the dominant seed shape is round and the recessive is wrinkled(w). The dominant trait for pod color is green and recessive is yellow (y). A plant with round seeds and green pods that i heterozygous only for the color trait is crossed with a plant that has wrinkled seeds and yellow pods, and the resulting F1 progeny are selfed(self fertilized).
In peas, the dominant seed shape is round ---W
-the recessive is wrinkled-------w
-dominant trait for pod color is green -----Y
recessive is yellow ---------y
round seeds and green pods that i heterozygous-COLOR------------ WW Yy
plant that has wrinkled seeds and yellow pods,----------wwyy
Gametes
wy
Ratio
W Y
wy W Y
round
green
4/16= 1/4
W y
wy W Y
round
green
4/16= 1/4
W y
wy W y
round
yellow
4/16= 1/4
W y
wy W y
round
yellow
4/16= 1/4
F2 cross wy W Y round, green x wy W y round yellow
Wy
Wy
wy
wy
WY
WY Wy
round green
WY Wy
round green
WY wy
wrinkled green
WY wy
wrinkled green
Wy
Wy Wy
round yellow
Wy Wy
round yellow
Wy wy
round yellow
Wy wy
round yellow
wY
wY Wy
round green
wY Wy
round green
wY wy
wrinkled green
wY wy
wrinkled green
wy
wy Wy
round yellow
wy Wy
round yellow
wy wy
wrinkled yellow
wy wy
wrinkled yellow
Wy
wy
WY
WY Wy
round green
2/16
WY wy
wrinkled green
2/16
Wy
Wy Wy
round yellow
2/16
Wy wy
round yellow
2/16
wY
wY Wy
round green
2/16
wY wy
wrinkled green
2/16
wy
wy Wy
round yellow
2/16
wy wy
wrinkled yellow
2/16
Gametes
wy
Ratio
W Y
wy W Y
round
green
4/16= 1/4
W y
wy W Y
round
green
4/16= 1/4
W y
wy W y
round
yellow
4/16= 1/4
W y
wy W y
round
yellow
4/16= 1/4