Final answer:
The rainforest and coral reef biomes are the most biodiverse, with rainforests having high biodiversity due to warm temperatures and abundant rain, and coral reefs supporting diverse marine life.
Step-by-step explanation:
The two biomes that contain the greatest biodiversity are B) Rainforest and coral reef. Rainforests, particularly tropical rainforests, are renowned for their rich and varied plant and animal life, due to their warm temperatures and abundant rainfall which supports high levels of primary productivity. Coral reefs, while not terrestrial biomes but marine ecosystems, also exhibit exceptional biodiversity, housing a myriad of species from colorful fish to diverse forms of coral and other invertebrates.
In contrast, biomes such as the tundra and deserts are characterized by extreme temperatures and lower levels of precipitation, which result in a much lower level of biodiversity. Tundra landscapes, both Arctic and Alpine, are noted for their cold climate and limited plant and animal life. Deserts, although they can be hot or cold, have sparse vegetation and animal populations due to limited water availability.