Question

activity b:
genetics basics
get the gizmo ready:

• click clear.
• drag a black mouse and a white mouse into the parent boxes.

introduction: inherited traits are encoded on a molecule called dna (deoxyribonucleic acid). genes are segments of dna that control a particular trait. most genes have several different versions, or alleles. the genotype is the allele combination an organism has.
question: how do alleles determine fur color?

1. observe: turn on show genotype. move your cursor over a mouse to see its genotype.

a. what is the genotype of the black parent? ____ white parent? ____
these mice are homozygous for fur color, meaning both alleles are the same.
b. click breed. what is the genotype of the offspring mice? ______
these mice are heterozygous for fur color, meaning the alleles are different.

Explanation:

Part A

In typical mouse genetics (using Gizmo), black fur is often dominant (let's assume allele \( B \)) and white is recessive (\( b \)). Homozygous black would have \( BB \), homozygous white \( bb \).

When breeding \( BB \) (black) and \( bb \) (white), offspring inherit one allele from each parent. So each offspring gets \( B \) from black parent and \( b \) from white parent, resulting in \( Bb \).

Answer:

Black parent: \( BB \)
White parent: \( bb \)

Part B