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.



Answer :

To determine the correct statements, we need to analyze the genotypes resulting from the given Punnett squares.

First Generation Punnett Square:
[tex]\[ \begin{array}{|c|c|c|} \hline & t & t \\ \hline T & Tt & Tt \\ \hline T & Tt & Tt \\ \hline \end{array} \][/tex]

From the First Generation Punnett square:
- All offspring have the genotype Tt.

Second Generation Punnett Square:
[tex]\[ \begin{array}{|c|c|c|} \hline & T & t \\ \hline T & TT & Tt \\ \hline t & Tt & tt \\ \hline \end{array} \][/tex]

From the Second Generation Punnett square:
- The offspring can have the genotypes TT, Tt, or tt.

Analyzing the Statements:

1. Plants with short stems are homozygous for that trait.
- Short stems are denoted by the recessive allele (tt). To exhibit the recessive trait, the plant must have two recessive alleles (tt).
- Therefore, plants with short stems (tt) are indeed homozygous for the short stem trait.

2. Plants with tall stems are always homozygous for that trait.
- Tall stems are denoted by the dominant allele (T).
- Tall plants can have genotypes TT (homozygous dominant) or Tt (heterozygous).
- Therefore, it is false to say that plants with tall stems are always homozygous for that trait since they can also be heterozygous (Tt).

Thus, the correct statements are:

- Plants with short stems are homozygous for that trait.

Plants with tall stems are not always homozygous for that trait, so this statement is false.