Which of the following is NOT a characteristic of animals?

Animals are characterized by several defining features that distinguish them from other life forms. Among these characteristics, multicellular organization, heterotrophic nutrition, and the capability for active movement at some stage of development are essential aspects of animal biology.

In contrast, the presence of a cell wall is not a trait found in animals. While many plants, fungi, and bacteria have cell walls that provide structure and support, animal cells are surrounded by a flexible plasma membrane instead. This absence of a cell wall allows for greater flexibility and mobility in animal cells, which is crucial for various functions such as movement and interaction with their environment.

Thus, identifying the presence of a cell wall as not characteristic of animals aligns with our understanding of animal physiology and cellular structure.