The statement that has exceptions is:
c. sexual reproduction requires two parents, whereas asexual reproduction requires only one parent.
While sexual reproduction typically involves the combination of genetic material from two parents, there are exceptions. For example, some organisms can reproduce sexually through processes like self-fertilization (e.g., certain plants and hermaphroditic animals), where one individual acts as both the male and female parent. In addition, some forms of asexual reproduction can involve more complex interactions, such as fragmentation or budding in certain species, which may involve multiple individuals in a way that blurs the lines of parental roles.
The other statements generally hold true without exceptions.