Answer :
To solve this genetic cross problem, let's break it down step-by-step.
1. First Cross: PP (purple) x pp (white)
- The genotype of the first parent plant is "PP" and that of the second parent is "pp".
- "P" is the dominant allele for purple flowers and "p" is the recessive allele for white flowers.
Possible Gametes:
- Parent with genotype PP can produce only gametes with the "P" allele.
- Parent with genotype pp can produce only gametes with the "p" allele.
Punnett Square for the First Cross:
```
| | P | P |
|---|---|---|
| p | Pp| Pp|
| p | Pp| Pp|
```
- All the offspring will have the genotype "Pp".
Phenotypic Outcome:
- Since "P" is dominant, all offspring will have purple flowers.
Probability of Purple Flowers:
- 100% or 1.0 (all offspring are purple).
2. Second Cross: Pp (from first cross) x pp (white)
- The genotype of the offspring from the first cross is "Pp" and that of the second parent is "pp".
Possible Gametes:
- Offspring with genotype Pp can produce gametes with "P" and "p".
- Parent with genotype pp can produce only gametes with the "p" allele.
Punnett Square for the Second Cross:
```
| | P | p |
|---|---|---|
| p | Pp| pp|
| p | Pp| pp|
```
- The possible genotypes for the offspring are "Pp" and "pp".
Phenotypic Outcome:
- The "Pp" offspring will have purple flowers.
- The "pp" offspring will have white flowers.
Probability of Homozygous Dominant (PP):
- In this cross, there are no "PP" genotypes possible.
- The probability of homozygous dominant genotype (PP) is 0%.
So, the correct answers are:
1. The possibility that the offspring will have purple flowers is 1.0 (or 100%).
2. If an offspring from this cross mates with a pp, the possibility of homozygous dominant genotype for the flowers will be 0.0.
1. First Cross: PP (purple) x pp (white)
- The genotype of the first parent plant is "PP" and that of the second parent is "pp".
- "P" is the dominant allele for purple flowers and "p" is the recessive allele for white flowers.
Possible Gametes:
- Parent with genotype PP can produce only gametes with the "P" allele.
- Parent with genotype pp can produce only gametes with the "p" allele.
Punnett Square for the First Cross:
```
| | P | P |
|---|---|---|
| p | Pp| Pp|
| p | Pp| Pp|
```
- All the offspring will have the genotype "Pp".
Phenotypic Outcome:
- Since "P" is dominant, all offspring will have purple flowers.
Probability of Purple Flowers:
- 100% or 1.0 (all offspring are purple).
2. Second Cross: Pp (from first cross) x pp (white)
- The genotype of the offspring from the first cross is "Pp" and that of the second parent is "pp".
Possible Gametes:
- Offspring with genotype Pp can produce gametes with "P" and "p".
- Parent with genotype pp can produce only gametes with the "p" allele.
Punnett Square for the Second Cross:
```
| | P | p |
|---|---|---|
| p | Pp| pp|
| p | Pp| pp|
```
- The possible genotypes for the offspring are "Pp" and "pp".
Phenotypic Outcome:
- The "Pp" offspring will have purple flowers.
- The "pp" offspring will have white flowers.
Probability of Homozygous Dominant (PP):
- In this cross, there are no "PP" genotypes possible.
- The probability of homozygous dominant genotype (PP) is 0%.
So, the correct answers are:
1. The possibility that the offspring will have purple flowers is 1.0 (or 100%).
2. If an offspring from this cross mates with a pp, the possibility of homozygous dominant genotype for the flowers will be 0.0.