Which one of the following structures is not found in case of asexual reproduction?

Asexual reproduction involves the production of offspring by a single organism without the fusion of specialized reproductive cells. The structures mentioned in the other options are all characteristic of asexual processes: Conidia are non-motile asexual spores in fungi; Gemmules are internal asexual buds produced by sponges; and Zoospores are motile asexual spores found in algae and some fungi.

In contrast, Gametes (such as sperm and egg cells) are specialized haploid cells produced specifically for sexual reproduction. The defining feature of sexual reproduction is the fusion of two gametes (syngamy) to form a diploid zygote. Because asexual reproduction does not involve the fusion of reproductive cells or genetic recombination between two parents, gametes are not found in this mode of reproduction.