dentonboys03
Answered

Select all the correct answers.

A particular plant has two alleles that control the length of its stem. [tex]$T$[/tex] represents the dominant allele that codes for a tall stem, and [tex]$t$[/tex] 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
[tex]$T$[/tex] & [tex]$Tt$[/tex] & [tex]$Tt$[/tex] \\
\hline
[tex]$T$[/tex] & [tex]$Tt$[/tex] & [tex]$Tt$[/tex] \\
\hline
\end{tabular}

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

A. Plants with short stems are homozygous for that trait.

B. Plants with tall stems are always homozygous for that trait.

C. Both parent plants in the second generation are heterozygous.

D. Both parent plants in the second generation are homozygous.



Answer :

GinnyAnswer
Based on the Punnett squares provided and the information about the alleles controlling the plant's stem length, let's analyze the genotype outcomes.

### First Generation:
The first generation cross is between two parents, each with genotype `Tt` (heterozygous):

| First Generation | [tex]$t$[/tex] | [tex]$t$[/tex] |
|------------------|-----|-----|
| [tex]$T$[/tex] | [tex]$Tt$[/tex]| [tex]$Tt$[/tex]|
| [tex]$T$[/tex] | [tex]$Tt$[/tex]| [tex]$Tt$[/tex]|

From the first generation cross, all the offspring (`Tt`) will be heterozygous, resulting in tall stems due to the presence of the dominant allele [tex]$T$[/tex].

### Second Generation:
The second generation cross is:

| Second Generation | [tex]$T$[/tex] | [tex]$t$[/tex] |
|-------------------|-----|-----|
| [tex]$T$[/tex] | [tex]$TT$[/tex]| [tex]$Tt$[/tex]|
| [tex]$t$[/tex] | [tex]$Tt$[/tex]| [tex]$tt$[/tex]|

From the second generation cross, the genotypes of the offspring are as follows:
- [tex]$TT$[/tex]: Homozygous dominant (tall stems)
- [tex]$Tt$[/tex]: Heterozygous (tall stems)
- [tex]$tt$[/tex]: Homozygous recessive (short stems)

### Analyzing the Statements:
1. Plants with short stems are homozygous for that trait.
- This statement is true. Only the genotype `tt` results in short stems, and this genotype is homozygous recessive.

2. Plants with tall stems are always homozygous for that trait.
- This statement is false. Plants with tall stems can be either homozygous dominant ([tex]$TT$[/tex]) or heterozygous ([tex]$Tt$[/tex]).

3. Both parent plants in the second generation are heterozygous.
- This statement is true. The Punnett square shows that both parents in the second generation have the genotype [tex]$Tt$[/tex].

4. Both parent plants in the second generation are homozygous.
- This statement is false. As previously mentioned, both parents in the second generation have the genotype [tex]$Tt$[/tex], which is heterozygous.

### Conclusion:
The correct statements based on the analysis above are:
- Plants with short stems are homozygous for that trait.
- Both parent plants in the second generation are heterozygous.

So, the true answers are:
- Plants with short stems are homozygous for that trait.
- Both parent plants in the second generation are heterozygous.