Question

Echidnas hatch from an egg and develop bristles as they mature. Two echidnas have different parents. One has thick bristles while the other has thin bristles. Why do the echidnas have bristles with different thicknesses?
Responses

a
The echidnas have different versions of the gene for bristle thickness. The genes are a different thickness in each echidna’s bristles.
The echidnas have different versions of the gene for bristle thickness. The genes are a different thickness in each echidna’s bristles.

b
The echidnas have different versions of the gene for bristle thickness, which instruct for different proteins that connect in different ways to make bristles of different thicknesses.
The echidnas have different versions of the gene for bristle thickness, which instruct for different proteins that connect in different ways to make bristles of different thicknesses.

c
Each echidna has a different bristle thickness because offspring from different parents will have bristles of different thicknesses.
Each echidna has a different bristle thickness because offspring from different parents will have bristles of different thicknesses.

d
Each echidna has a different bristle thickness because they have different versions of the gene for bristle thickness that connect together to make different bristle thicknesses.

Answer 1

d
Each echidna has a different bristle thickness because they have different versions of the gene for bristle thickness that connect together to make different bristle thicknesses.