An organism that shows a dominant trait (purple flowers) , is either homozygous or heterozygous for the dominant allele: By performing a test cross, with a homozygous recessive individual the unknown genotype can be determined: Part A: Fill in pre-drawn Punnett squares (remember vou"Il need to test BOTH heterozygous and homozygous)- Part 8: determine the offspring genotypes- PPXPP Pp x PP Part C: determine the offspring phenotypes- PP XPp Pp X PP'

Question

An organism that shows a dominant trait (purple flowers) , is either homozygous or heterozygous for the dominant allele: By performing a test cross, with a homozygous recessive individual the unknown genotype can be determined: Part A: Fill in pre-drawn Punnett squares (remember vou"Il need to test BOTH heterozygous and homozygous)- Part 8: determine the offspring genotypes- PPXPP Pp x PP Part C: determine the offspring phenotypes- PP XPp Pp X PP'

Answer 1

Part A:

Homozygous dominant x Homozygous recessive:

| | P | p |
|---|---|---|
| P | PP | Pp |
| P | PP | Pp |

Heterozygous dominant x Homozygous recessive:

| | P | p |
|---|---|---|
| P | Pp | Pp |
| P | Pp | Pp |

Part B:

Homozygous dominant x Homozygous recessive:

- All offspring will be heterozygous dominant (Pp)

Heterozygous dominant x Homozygous recessive:

- 50% of offspring will be heterozygous dominant (Pp)
- 50% of offspring will be homozygous dominant (PP)

Part C:

Homozygous dominant x Homozygous recessive:

- All offspring will have the dominant phenotype (purple flowers)

Heterozygous dominant x Homozygous recessive:

- 100% of offspring will have the dominant phenotype (purple flowers)

Answer 2

To determine the offspring genotypes and phenotypes using a test cross, we need to fill in the Punnett squares for both the homozygous and heterozygous crosses.

Part A: Filling in the Punnett squares

1. Homozygous dominant (PP) crossed with homozygous recessive (pp):

| P | p |
---------------------
P | PP | Pp |
---------------------
p | Pp | pp |

2. Heterozygous (Pp) crossed with homozygous recessive (pp):

| P | p |
---------------------
P | PP | Pp |
---------------------
p | Pp | pp |

Part B: Determine the offspring genotypes

1. Homozygous dominant (PP) crossed with homozygous recessive (pp):
All offspring will have the genotype Pp.

2. Heterozygous (Pp) crossed with homozygous recessive (pp):
The offspring can have two possible genotypes: Pp or pp.

Part C: Determine the offspring phenotypes

1. Homozygous dominant (PP) crossed with homozygous recessive (pp):
All offspring will have the phenotype of purple flowers.

2. Heterozygous (Pp) crossed with homozygous recessive (pp):
Some of the offspring will have the phenotype of purple flowers (Pp),
while others will have the phenotype of white flowers (pp).

So, the genotypes of the offspring from the test cross are Pp and pp, and the phenotypes are purple and white flowers.