Question

select all the offspring phenotypes that could be produced from a bbee x bbee cross (shown above).

black fur, red eyes
black fur, black eyes
white fur, black eyes
white fur, red eyes

Explanation:

Identify parental genotypes and alleles

We are given a cross between two mice: \(BbEE \times bbee\).
Let's analyze the alleles for each gene:

• Gene 1 (Fur color): Alleles \(B\) (black) and \(b\) (white/brown, depending on standard mouse genetics, but let's look at the cross).
• Gene 2 (Eye color): Alleles \(E\) (black eyes) and \(e\) (red eyes).

The parents are:

• Parent 1: \(BbEE\) (black fur, black eyes)
• Parent 2: \(bbee\) (white fur, red eyes)

Determine offspring genotypes for fur color

Using a Monohybrid Cross for the fur color gene:

• Parent 1 contributes either \(B\) or \(b\).
• Parent 2 contributes only \(b\).

The resulting offspring genotypes for fur color are:

• \(Bb\) (black fur)
• \(bb\) (white fur)

Both black fur and white fur phenotypes are possible.

Determine offspring genotypes for eye color

Using a Monohybrid Cross for the eye color gene:

• Parent 1 contributes only \(E\).
• Parent 2 contributes only \(e\).

All offspring will have the genotype:

• \(Ee\) (black eyes)

Since \(E\) is dominant, all offspring will have black eyes. No offspring can have red eyes (\(ee\)).

Combine the traits for the dihybrid cross

Using the principles of a Dihybrid Cross, we combine the possible phenotypes:

• Fur color: black (\(Bb\)) or white (\(bb\))
• Eye color: black eyes (\(Ee\)) only

Therefore, the possible offspring phenotypes are:

1. Black fur, black eyes (\(BbEe\))
2. White fur, black eyes (\(bbEe\))

Match with the given options

Let's evaluate the choices:

• "black fur, red eyes": Impossible (requires \(ee\)).
• "black fur, black eyes": Possible (\(BbEe\)).
• "white fur, black eyes": Possible (\(bbEe\)).
• "white fur, red eyes": Impossible (requires \(ee\)).

Answer:

• black fur, red eyes
• black fur, black eyes (Correct answer)
• white fur, black eyes (Correct answer)
• white fur, red eyes