Question

Heterochromia is when a human or animal has two different eye colors. Heterochromia can have many different causes. The cause of heterochromia determines its type and if it is heritable or not. The person in the image has heterochromia that occurred from a mutation during mitosis and is only found in the somatic cells of their body.
Which two statements correctly describe the heterochromia mutation in the passage?

A.
The mutation did not occur by chance.

B.
The mutation did not affect the genotype of the cells.

C.
The mutation was inherited from the person's parents.

D.
The mutation occurred after the formation of the embryo.

E.
The mutation will not be passed onto the person's offspring.

Answer 1

Correct answers: D and E.

- D: True — a mutation during mitosis in somatic cells occurs after fertilization/embryo formation.
- E: True — because it is confined to somatic cells (not in the germ line), it cannot be transmitted to offspring.

(For clarity: the mutation does change the genotype of the affected somatic cells, so B is false; it was not inherited from the parents, so C is false; and mutations typically occur by chance or from mutagens, so A is not supported.)