Question

Two rabbits have different parents. One rabbit has ears that flop over, and the other rabbit has ears that stand straight up. Why do the rabbits have ears with different shapes?
Responses

a
The rabbits have different versions of the gene for ear shape. The genes are only standing straight up in the cells of one rabbit’s ears.
The rabbits have different versions of the gene for ear shape. The genes are only standing straight up in the cells of one rabbit’s ears.

b
The rabbits have different versions of the gene for ear shape, which instruct for different proteins that connect in different ways to make different ear shapes.
The rabbits have different versions of the gene for ear shape, which instruct for different proteins that connect in different ways to make different ear shapes.

c
Each rabbit has a different ear shape because offspring from different parents will have different ear shapes.
Each rabbit has a different ear shape because offspring from different parents will have different ear shapes.

d
Each rabbit has a different ear shape because they have different versions of the gene for ear shape that connect together to make different ear shapes.

Answer 1

b

Different versions (alleles) of the ear‑shape gene encode different proteins or protein activity during ear development, producing structural differences (cartilage/ligaments/muscle) that make one rabbit’s ears flop and the other’s stand up. Options a and c are vague or incorrect; d is less clear about how gene products cause the shape.