Question

part b - diagramming a cross using a punnett square
punnett squares can be used to predict the two possible outcomes of the botanist’s test cross. the punnett square on the left shows the predicted result if the unknown plant is homozygous (gg); the punnett square on the right shows the predicted result if the unknown plant is heterozygous (gg).
drag the labels to the correct locations on the punnett squares. (g is the symbol for the green-pod allele and g is the symbol for the yellow-pod allele.) you can use a label once, more than once, or not at all.
view available hint(s)
test cross of homozygous
green pod plant
test cross of heterozygous
green pod plant
gg
g
g
gg
gg
reset
help

Explanation:

Step1: Analyze homozygous test cross

The unknown plant is homozygous (\(GG\)), and it's crossed with a yellow - pod plant (\(gg\)) (since test cross is usually with a homozygous recessive). The gametes from \(GG\) are all \(G\), and from \(gg\) are all \(g\). So the Punnett square for homozygous green - pod plant (\(GG\)) test cross:

• The top - left empty cell (above the Punnett square) for the homozygous cross should be \(G\) (gamete from \(GG\)).
• The right - side empty cell (next to the Punnett square) for the homozygous cross should be \(G\) (another gamete from \(GG\)).
• Inside the Punnett square cells: each cell will be \(Gg\) (because \(G\) from \(GG\) and \(g\) from \(gg\)).

Step2: Analyze heterozygous test cross

The unknown plant is heterozygous (\(Gg\)), and it's crossed with \(gg\). The gametes from \(Gg\) are \(G\) and \(g\), and from \(gg\) are all \(g\). So the Punnett square for heterozygous green - pod plant (\(Gg\)) test cross:

• The top - left empty cell (above the Punnett square) for the heterozygous cross should be \(G\) (one gamete from \(Gg\)).
• The right - side empty cell (next to the Punnett square) for the heterozygous cross should be \(g\) (another gamete from \(Gg\)).
• Inside the Punnett square cells: two cells will be \(Gg\) ( \(G\) from \(Gg\) and \(g\) from \(gg\)) and two cells will be \(gg\) ( \(g\) from \(Gg\) and \(g\) from \(gg\)).

For the homozygous (\(GG\)) test cross Punnett square:

• The top - left outside cell (above the square) is \(G\).
• The right - side outside cell (next to the square) is \(G\).
• All four cells inside the square are \(Gg\).

For the heterozygous (\(Gg\)) test cross Punnett square:

• The top - left outside cell (above the square) is \(G\).
• The right - side outside cell (next to the square) is \(g\).
• Two cells inside the square are \(Gg\) and two cells are \(gg\).

Answer:

Homozygous (\(GG\)) Test Cross Punnett Square:

• Top - left outside cell: \(G\)
• Right - side outside cell: \(G\)
• Inside cells: \(Gg\), \(Gg\), \(Gg\), \(Gg\)

Heterozygous (\(Gg\)) Test Cross Punnett Square:

• Top - left outside cell: \(G\)
• Right - side outside cell: \(g\)
• Inside cells: \(Gg\), \(gg\), \(Gg\), \(gg\) (arranged appropriately in the 2x2 square)