Which of the following categories includes organisms like birds and mammals?

The category that encompasses organisms like birds and mammals is indeed animals. This classification is based on various biological characteristics that distinguish animals from other life forms. Animals are multicellular, eukaryotic organisms that are primarily characterized by their ability to move independently at some stage of their life, their heterotrophic mode of nutrition (meaning they consume other organisms for energy), and their complex nervous systems that facilitate responses to stimuli.

Birds and mammals share specific traits that align with the broader characteristics of the animal kingdom, such as having a backbone, breathing through lungs, and reproducing either through live birth or laying eggs. This classification helps biologists understand the relationships and evolutionary history among different species, making it easier to study them in a systematic manner.