Question

organs work together to form body systems, and body systems work together to form ______. which choice below correctly completes the sentence? groups tissues populations organisms

Explanation:

生物的结构层次为：细胞构成组织，组织构成器官，器官构成系统，多个系统相互协作构成完整的生物体；种群是同一区域同种生物的集合，和个体结构层次无关。

Answer:

D. organisms