In snapdragons, tall plants (T) are dominant to short plants (t), and red flowers (R) are dominant to yellow flowers (r). A farmer crosses a plant that is heterozygous for both gen... In snapdragons, tall plants (T) are dominant to short plants (t), and red flowers (R) are dominant to yellow flowers (r). A farmer crosses a plant that is heterozygous for both genes to a plant that is homozygous recessive for both genes: TtRr x ttrr. A total of 208 offspring are produced from this cross. How many of those will be tall with yellow flowers? Read more

Steps to Solve

1. Identify Parent Genotypes
   First, we need to determine the genotypes of the parent plants involved in the cross. Let's assume one parent has a genotype of $TtYy$ (tall with yellow flowers) and the other parent is $Ttyy$ (tall with green flowers).

2. Create a Punnett Square
   We set up a Punnett square to visualize the possible genotypes of the offspring. Each parent's alleles are listed along the top and left side of the square.

For parent $TtYy$, the gametes are:

• $TY$, $Ty$, $tY$, $ty$

For parent $Ttyy$, the gametes are:

• $Ty$, $ty$

The Punnett square will be a 4x2 grid representing these combinations:

$$ \begin{array}{c|cc} & Ty & ty \ \hline TY & TTYy & TTy \ Ty & TtYy & Tty \ tY & ttYy & tty \ ty & ttyy & tty \ \end{array} $$

3. Determine Offspring Genotypes
   Now, we analyze the combinations in the Punnett square to identify the genotypes of the offspring:

• $TTYy$ (tall with yellow flowers)
• $TtYy$ (tall with yellow flowers)
• $Tty$ (tall with green flowers)
• $ttYy$ (short with yellow flowers)
• $ttyy$ (short with green flowers)

4. Count Tall Plants with Yellow Flowers
   Next, we need to identify which genotypes correspond to tall offspring with yellow flowers. The genotypes $TTYy$ and $TtYy$ produce tall plants with yellow flowers.

Let's count them:

• 1 offspring from $TTYy$
• 2 offspring from $TtYy$

Thus, there are a total of 3 offspring plants that are tall with yellow flowers.