What is the term for an asexual spore that uses a flagellum for movement and is associated with algae?

The term that describes an asexual spore capable of movement through the use of a flagellum, particularly in association with algae, is zoospore. Zoospores are motile and can swim through water, allowing them to disperse and potentially establish new populations in favorable environments. This mode of reproduction is significant for many freshwater and marine algae, enabling rapid propagation without the need for sexual reproduction.

Isogametes and heterogametes refer to types of gametes involved in sexual reproduction, where isogametes are indistinguishable in size and shape, while heterogametes differ in size or form. An oogonium refers specifically to a structure that produces eggs in certain organisms, such as in some algae and fungi, but it does not represent a spore or facilitate movement. Thus, among the options provided, zoospore is distinctly characterized by its asexual nature and motility, making it the correct answer.