Westonci.ca is the Q&A platform that connects you with experts who provide accurate and detailed answers. Connect with professionals ready to provide precise answers to your questions on our comprehensive Q&A platform. Discover detailed answers to your questions from a wide network of experts on our comprehensive Q&A platform.

Select all the correct answers.

A particular plant has two alleles that control the length of its stem. T represents the dominant allele that codes for a tall stem, and t represents the recessive allele that codes for a short stem. Based on the Punnett squares, which two statements are true about the genotype of the plant's stem length?

\begin{tabular}{|c|c|c|}
\hline
First Generation & [tex]$t$[/tex] & [tex]$t$[/tex] \\
\hline
T & Tt & Tt \\
\hline
T & Tt & Tt \\
\hline
\end{tabular}

\begin{tabular}{|c|c|c|}
\hline
Second Generation & T & [tex]$t$[/tex] \\
\hline
T & TT & Tt \\
\hline
[tex]$t$[/tex] & Tt & tt \\
\hline
\end{tabular}

- Plants with short stems are homozygous for that trait.

Sagot :

Let's analyze the results in the question based on the Punnett squares provided to understand which statements are true regarding the stem length of the plant.

### First Generation Punnett Square:
```
\begin{tabular}{|c|c|c|}
\hline
First Generation & [tex]$t$[/tex] & [tex]$t$[/tex] \\
\hline
T & Tt & Tt \\
\hline
T & Tt & Tt \\
\hline
\end{tabular}
```
In the first generation:
- All offspring have the Tt genotype.
- Since T is dominant over t, all offspring will have tall stems.
- Therefore, there will be no plants with short stems in this generation.

### Second Generation Punnett Square:
```
\begin{tabular}{|c|c|c|}
\hline
Second Generation & T & [tex]$t$[/tex] \\
\hline
T & TT & Tt \\
\hline
[tex]$t$[/tex] & Tt & [tex]$tt$[/tex] \\
\hline
\end{tabular}
```
In the second generation:
- There are four possible genotypes: TT, Tt, Tt, tt.
- TT and Tt result in tall stems because the presence of at least one dominant T allele results in a tall stem.
- The genotype tt results in a short stem since both alleles are recessive.

Among these four possible genotypes:
- The tt combination occurs once, making the probability of getting a plant with a short stem [tex]\( \frac{1}{4} \)[/tex] or 0.25.

### Statements Analysis:
Given that we have calculated the first and second generation probabilities:
- First generation: Probability of short stems [tex]\( \frac{first\_gen\_short\_stems}{total} = 0 \)[/tex].
- Second generation: Probability of short stems [tex]\( \frac{second\_gen\_short\_stems}{total} = \frac{1}{4} \)[/tex] or 0.25.

### True Statements:
1. In the first generation, there will be no plants with short stems.
2. In the second generation, there is a [tex]\( \frac{1}{4} \)[/tex] chance, or 0.25 probability, of plants having short stems.

Therefore, the two correct statements based on the Punnett squares and the genotypic probabilities are:

- In the first generation, all plants are tall (Tt), and none are short stem plants.
- In the second generation, there's a [tex]\( \frac{1}{4} \)[/tex] or 0.25 probability of a plant having short stems (tt).

These statements match and are supported by the detailed step-by-step analysis above.