Gregor crossed a true breeding yellow,rough pea plant with a true breeding green, smooth plant.?

Question

All of the off spring were green, rough plants. He then used these F1 plants for back crosses to each parent. What are the genotypes and phenotypes of the offspring of these 2 back crosses?

Answer 1

If G represents dominant allele for green, g for yellow.
If R represents dominant allele for rough, r for smooth.
for the backcross between F1 and the green ,smooth parent
GGRr -green and rough
Ggrr - green and smooth
GGrr - green and smooth
GGRR - green and rough
for the backcross between F2 and the yellow, rough parent
GgRR - green and rough
GgRr - green and rough
ggRr - yellow and rough
ggRR - yellow and rough

Answer 2

Since the offspring in the F1 were green, rough, that tells us that green and rough are the dominant forms of the traits. The yellow, rough parent must have been ggRR; the green, smooth parent must have been GGrr; the F1 must have been GgRr.

Backcross ggRR x GgRr
Your Punnett square does not have to be 4x4 because the ggRR parent only makes gametes that are gR. So really you have just one row in the Punnett square with gR at the left. Put the gametes from the second parent on the top: GR, Gr, gR, gr. You can take it from there.

Backcross GGrr x GgRr the same way.

I don't think you need more help from this point.

Answer 3

because of the fact the offspring interior the F1 have been green, tough, that tells us that green and tough are the dominant varieties of the features. The yellow, tough parent could desire to have been ggRR; the fairway, tender parent could desire to have been GGrr; the F1 could desire to have been GgRr. Backcross ggRR x GgRr Your Punnett sq. would not could desire to be 4x4 because of the fact the ggRR parent purely makes gametes that are gR. So fairly you have in basic terms one row interior the Punnett sq. with gR on the left. placed the gametes from the 2d parent on the precise: GR, Gr, gR, gr. you could take it from there. Backcross GGrr x GgRr an identical way. i do no longer think of you prefer extra help from this factor.