Question

if ( b ) represents the allele for black eyes (dominant) and ( b ) represents the allele for orange eyes (recessive), what would be the phenotypic ratio of a cross between a heterozygous black - eyed mendalien and an orange - eyed mendalien?
3 black : 1 orange
1 black : 1 orange
1 black : 3 orange
0 black : 1 orange
1 black : 0 orange

Explanation:

Step1: Determine the genotypes

A heterozygous black - eyed MendAlien has the genotype \( Bb \), and an orange - eyed MendAlien has the genotype \( bb \) (since orange eyes are recessive).

Step2: Set up the Punnett square

The cross is \( Bb\times bb \). The gametes from \( Bb \) are \( B \) and \( b \), and the gametes from \( bb \) are \( b \) and \( b \).
The Punnett square is:

	\( b \)	\( b \)
\( b \)	\( bb \)	\( bb \)

Step3: Analyze the phenotypes

\( Bb \) (black eyes) and \( bb \) (orange eyes). There are 2 \( Bb \) (black - eyed) and 2 \( bb \) (orange - eyed) in the offspring.

Answer:

1 black : 1 orange