Some species of male water striders forcibly copulate with females. in these species, males are often equipped with exaggerated grasping structures, while females have structures that obstruct the male's grip. such a situation could arise through:

Sexual antagonistic co-evolution

Explanation:

Based on the information provided within the question it can be said that such a situation could arise through Sexual antagonistic co-evolution. This refers to evolution between males and females of a species in which they change over time in order to counteract their mate's sex traits, allowing them to maximize their reproductive success. Such as in this scenario where the females have evolved and gained structures that obstruct the male's grip.

she forgot to record a transaction

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.