Final answer:
Viroids are plant pathogens that cause disease in plants and lead to significant agricultural losses. These small, single-stranded RNA particles can devastate crops like potatoes and tomatoes, affecting the agricultural industry and indirectly human populations.
Step-by-step explanation:
Viroids cause disease in plants. They are simple plant pathogens that consist of small, single-stranded, circular RNA particles. Viroids lack a protective protein coat, differing from viruses in this and other respects. They can only replicate within a host cell, leveraging the host's cellular machinery for replication. Viroids do not produce proteins but are capable of self-replication of their RNA molecule.
The economic significance of viroids is considerable, as they are responsible for crop failures and substantial financial losses in agriculture. For instance, viroids have affected various economically important crops such as potatoes, tomatoes, cucumbers, and avocados, leading to reductions in both the quantity and quality of these agricultural products.
While plant viruses cannot infect humans directly, the impact on human populations is still felt through the agricultural industry, where the loss of crops can lead to economic instability and scarcity of food products.