What method of reproduction do seedless plants primarily utilize?

Seedless plants primarily utilize asexual reproduction through spores. This method allows them to reproduce without the need for seeds, which is a characteristic feature of seed-producing plants. Spores are typically unicellular, and they can develop into a new organism without fertilization. This process is particularly effective in environments where conditions are suitable for rapid growth.

Spores can be produced in large quantities, increasing the chances that some will find favorable conditions to germinate and grow. In many seedless plants, such as ferns and mosses, the life cycle includes a dominant gametophyte stage that produces gametes, but the broader reproductive strategy relies on the more widespread and dispersible spores to establish new plants.

The other methods listed, such as vegetative propagation and binary fission, do occur in different groups of organisms but are not the primary reproductive strategies for seedless plants. Vegetative propagation is often associated with certain flowering plants, while binary fission is specific to prokaryotes and some single-celled organisms, not typically applicable to the more complex structures of seedless plants. Thus, asexual reproduction through spores is the key method for seedless plants, allowing them to thrive in diverse environments.