Final answer:
In situations approved under 45 CFR 46.406 where only one parental consent is required for research involving more than minimal risk and no direct benefit to the child, examples include an absentee, deceased, or incompetent parent, or one parent holding sole custody.
Step-by-step explanation:
Under 45 CFR 46.406, research that presents more than minimal risk and offers no direct benefit to child subjects typically requires consent from both parents. However, consent from only one parent is justifiable in certain circumstances. These circumstances include when the other parent is dead, not known, judged to be incompetent, not reasonably available, or when only one parent has legal responsibility for the care and custody of the child.
One justified reason for obtaining consent from only one parent is if the other parent is dead. Other scenarios such as the other parent not being known, the other parent being judged as incompetent, the other parent not being reasonably available, or the case where only one parent has full legal responsibility for the care and custody of the child also provide sufficient justification for seeking consent from just one parent.
Informed consent is crucial and requires that potential risks and benefits be clearly outlined to participants or their legal guardians, as with children, so they can make an informed decision regarding their participation in a study.