In: Biology
2. Cross a homozygous tall yellow seeded plant with a homozygous short green seeded plant. This is called the P1 cross, and it will produce offspring called the F1 generation. Tallness is dominant to shortness, so use a capital T to represent the tallness allele and lower case t to represent the shortness allele. Yellow seeds are dominant to green sees, so use a capital Y to represent the yellow seed allele and a lower case y to represent the green seed allele.
a) What is the genotype of the tall plant?
b) What gametes can the tall plant make?
c) What is the genotype of the short plant?
d) What gametes can the short plant make?
e) Create a punnett square explaining this
f) What is the genotypic ratio of the F1 plants?
g) What is the phenotypic ration of the F1 plants?
Homozygous tall yellow seeded plant - TTYY.
Homozygous short green seeded plant - ttyy.
P1 cross - TTYY X ttyy
Gametes formed TY ty
F1 Generation TtYy(tall yellow seeded plant ) X TtYy
F1 gametes TY, Ty, tY and ty TY, Ty, tY and ty
F2 Generation
Male/Female | TY | Ty | tY | ty |
TY | TTYY(tall yellow seeded plant ) | TTYy(tall yellow seeded plant ) | TtYY(tall yellow seeded plant ) | TtYy(tall yellow seeded plant ) |
Ty | TTYy(tall yellow seeded plant ) | TTyy(tall green seeded plant ) | TtYy(tall yellow seeded plant ) | Ttyy(tall green seeded plant ) |
tY | TtYY(tall yellow seeded plant ) | TtYy(tall yellow seeded plant ) | ttYY(short yellow seeded plant ) | ttYy(short yellow seeded plant ) |
ty | TtYy(tall yellow seeded plant ) | Ttyy(tall green seeded plant ) | ttYy(short yellow seeded plant ) | ttyy(short green seeded plant ) |
a) The genotype of the tall plant - TT and Tt.
b) Gametes can the tall plant make - T for TT(homozygous) and
T and t for Tt (heterozygous).
c) The genotype of the short plant - tt.
d) Gametes can the short plant make - t.
e) Punnett square created above.
f) The genotypic ratio of the F1 plants - no genotypic ratio, all are TtYy.
But genotypic ratio in F2 generation - 1:2:2:4:1:2:1:2:1.
g) The phenotypic ration of the F1 plants - no phenotypic ratio, all are tall yellow seeded plants.But phenotypic ratio in F2 generation - 9:3:3:1.