Round seeds (R) are dominant to wrinkled seeds (r) and yellow seeds (Y) are dominant to green seeds (y). a true-breeding pea plant with round and yellow seeds is crossed to a true breeding plant with wrinkled and green seeds. The F1 progeny are allowed to self fertilize. What is the probability of obtaining a wrinkled, green seed in the F2

Respuesta :

Answer:

1/16 of the progeny is expected to be plants with wrinkled and green seeds, rryy

Explanation:

Available data:

  • Round seeds (R) are dominant to wrinkled seeds (r)
  • Yellow seeds (Y) are dominant to green seeds (y)
  • A true-breeding pea plant with round and yellow seeds is crossed to a true breeding plant with wrinkled and green seeds
  • The F1 progeny self fertilize

1st Cross:

Parentals) RRYY    x     rryy

Gametes)  RY, RY, RY, RY

                 ry, ry, ry, ry

F1) 100% RrYy

2nd Cross)

Parentals) RrYy    x    RrYy

Gametes) RY, Ry, rY, ry

                RY, Ry, rY, ry

Punnett square)   RY        Ry           rY        ry

                  RY    RRYY    RRYy    RrYY    RrYy

                  Ry     RRYy    RRyy     RrYy    Rryy

                  rY      RrYY    RrYy      rrYY    rrYy

                  ry       RrYy     Rryy      rrYy    rryy

F2) Genotype

  • 1/16 of the progeny is expected to be RRYY
  • 2/16 = 1/8 of the progeny is expected to be RRYy
  • 1/16 of the progeny is expected to be RRyy
  • 2/16 = 1/8 of the progeny is expected to be RrYY
  • 4/16 = 1/4 of the progeny is expected to be RrYy
  • 2/16 = 1/8 of the progeny is expected to be Rryy
  • 1/16 of the progeny is expected to be rrYY
  • 2/16 = 1/8 of the progeny is expected to be rrYy
  • 1/16 of the progeny is expected to be rryy

      Phenotype

  • 9/16 of the progeny is expected to be plants with round and yellow seeds R-Y-
  • 3/16 of the progeny is expected to be plants with round and green seeds R-yy
  • 3/16 of the progeny is expected to be plants with wrinkled and yellow seeds rrY-
  • 1/16 of the progeny is expected to be plants with wrinkled and green seeds rryy