Question
A tall pea plant is crossed with a short pea plant. All of the offspring that are produced are tall. Two of these tall offspring are crossed. The punnett squar for this second cross is shown.
what can be concluded from this cross.
what can be concluded from this cross.
Answers
GPT-4o mini
Given the scenario described, we have a situation involving pea plant height, where tall (T) is dominant over short (t).
1. **Initial Cross**: A tall pea plant (which could be homozygous tall TT or heterozygous Tt) is crossed with a short pea plant (tt). Since all offspring are tall, we can conclude that the tall parent must be heterozygous (Tt).
- Possible parental cross: Tt (tall) x tt (short)
- Offspring (F1 generation): 50% Tt (tall) and 50% tt (short)
- However, since all offspring are tall, the tall parent must be TT. If the initial tall plant were Tt, we'd expect a mix of tall and short offspring, which is not what happened.
Thus, it's concluded that the tall parent was homozygous TT.
2. **Second Cross of Tall Offspring**: Now, two of the tall offspring are crossed. If we assume these tall offspring are Tt (since they can only be heterozygous if one parent was Tt), the Punnett square for this cross would be:
```
T t
______________
T | TT | Tt |
|_________|_____|
t | Tt | tt |
|_________|_____|
```
From this square, we get the following ratios for the offspring:
- 25% TT (homozygous tall)
- 50% Tt (heterozygous tall)
- 25% tt (homozygous short)
### Conclusion:
From the second cross, we can conclude that while all tall progeny from the first cross are tall, a cross between two of those progeny (assuming they were Tt, or a mix of TT and Tt) can produce a mix of tall (75%) and short (25%) offspring. This demonstrates the segregation of alleles in inheritance and reveals how recessive traits can appear in subsequent generations.
1. **Initial Cross**: A tall pea plant (which could be homozygous tall TT or heterozygous Tt) is crossed with a short pea plant (tt). Since all offspring are tall, we can conclude that the tall parent must be heterozygous (Tt).
- Possible parental cross: Tt (tall) x tt (short)
- Offspring (F1 generation): 50% Tt (tall) and 50% tt (short)
- However, since all offspring are tall, the tall parent must be TT. If the initial tall plant were Tt, we'd expect a mix of tall and short offspring, which is not what happened.
Thus, it's concluded that the tall parent was homozygous TT.
2. **Second Cross of Tall Offspring**: Now, two of the tall offspring are crossed. If we assume these tall offspring are Tt (since they can only be heterozygous if one parent was Tt), the Punnett square for this cross would be:
```
T t
______________
T | TT | Tt |
|_________|_____|
t | Tt | tt |
|_________|_____|
```
From this square, we get the following ratios for the offspring:
- 25% TT (homozygous tall)
- 50% Tt (heterozygous tall)
- 25% tt (homozygous short)
### Conclusion:
From the second cross, we can conclude that while all tall progeny from the first cross are tall, a cross between two of those progeny (assuming they were Tt, or a mix of TT and Tt) can produce a mix of tall (75%) and short (25%) offspring. This demonstrates the segregation of alleles in inheritance and reveals how recessive traits can appear in subsequent generations.