The hearts and brains of different vertebrates exhibit a similar basic structural plan despite varying degrees of complexity. What type of organs do they represent, and which evolutionary phenomenon do they indicate?

Step-by-step solution

According to NCERT, vertebrate hearts and brains share the same fundamental structural plan and embryonic origin but have evolved to exhibit varying degrees of complexity. Such organs are classified as homologous organs. Homologous structures arise due to divergent evolution, where the same basic structure develops along different directions as adaptations to different needs. Analogous organs, on the other hand, arise due to convergent evolution and have different anatomical origins but similar functions. Answer: H