[Solution from source] Oomycetes are oogamous: the female gamete (egg) is large and non-motile while the male gamete is small, so the statement that the female gamete is smaller and motile is reversed and wrong. The definitions of isogametes and anisogametes are correct, and Chlamydomonas does show isogamy and anisogamy while Fucus is oogamous. Answer (3).