The boy and girl inherit genetic material from the father only. The boy and girl inherit genetic material from the mother only. The boy and girl inherit genetic material from both parents. The boy inherits genetic material from the father only and the girl inherits it from the mother only.
I gave my students this multiple choice question: Twins are born. One is a boy and one is a girl. Which statement is correct about their genetic makeup?

Only one answer is correct among these 4 choices:
- The boy and girl inherit genetic material from the father only.
- The boy and girl inherit genetic material from the mother only.
- The boy and girl inherit genetic material from both parents.
- The boy inherits genetic material from the father only and the girl inherits it from the mother only.

Could you tell me which one is correct?

The boy and girl inherit genetic material from both parents.