Ans. Biological classification can be challenging due to several factors. One challenge is the discovery of new species, especially in diverse ecosystems like rainforests or deep-sea environments. Another challenge is the interpretation of limited or incomplete data for certain organisms. Additionally, the advent of molecular techniques has sometimes led to reclassification of organisms based on genetic similarities, which can be controversial. Overall, the dynamic nature of biological classification and the complexities of the natural world pose ongoing challenges for scientists in this field.