Final answer:
The key terms listed at the beginning of the section in biology are relevant and important concepts. They usually fall into the same classification taxa and help students demonstrate mastery of the learning objectives.
Step-by-step explanation:
The key terms listed at the beginning of the section in biology have the common characteristic of being relevant and important concepts that will be covered in the chapter. These terms are defined in context and also listed in the glossary for easy reference.
Furthermore, the key terms usually fall into the same classification taxa. For example, if the section is about animals, the key terms might include terms related to different animal groups such as mammals, birds, reptiles, etc.
Lastly, the key terms are intended to help students demonstrate mastery of the learning objectives. They are closely aligned to the content and review questions, which means that understanding these key terms is crucial to understand the main concepts of the chapter.