Question

a grey fur dog (gg) is crossed with a black fur dog (gg). complete the punnett square. put the grey dog on the top row using the dominant allele first.

Explanation:

Step1: Determine the gametes

The grey - fur dog (Gg) can produce two types of gametes: G and g. The black - fur dog (gg) can only produce g gametes.

Step2: Fill the Punnett square

Place the gametes of the grey - fur dog (G and g) on the top row (dominant allele G first) and the gametes of the black - fur dog (g and g) on the left - hand column.
The top - left box is filled with the combination of the top - row first allele (G) and the left - column first allele (g), so it is Gg.
The top - right box is filled with the combination of the top - row second allele (g) and the left - column first allele (g), so it is gg.
The bottom - left box is filled with the combination of the top - row first allele (G) and the left - column second allele (g), so it is Gg.
The bottom - right box is filled with the combination of the top - row second allele (g) and the left - column second allele (g), so it is gg.

The completed Punnett square:

	G	g
g	Gg	gg

Answer:

The top - row boxes from left to right: G, g; The left - hand column boxes from top to bottom: g, g; The interior boxes from top - left to bottom - right: Gg, gg, Gg, gg.