Which type of reproduction involves only one organism?

Asexual reproduction involves only one organism, making it the correct answer. This form of reproduction allows an organism to produce offspring without the involvement of gametes from two different parents. Common methods of asexual reproduction include processes such as binary fission, budding, and vegetative propagation, where a new individual is formed from a part of the parent organism.

In contrast, sexual reproduction requires the contribution of genetic material from two parents, leading to increased genetic diversity but necessitating the involvement of both male and female gametes. Bisexual reproduction is another term often used to describe organisms that have both male and female reproductive structures, emphasizing the need for two parents to contribute to the offspring. Clonal reproduction typically refers to a form of asexual reproduction where an organism creates a clone, but it still fundamentally relies on a single parent organism, similar to asexual reproduction.

The essence of asexual reproduction lies in its simplicity and efficiency, allowing rapid population increases under favorable conditions without the need for mate finding or courtship behaviors.