Cell wall for higher growth rates in diatoms. In brown algae, phlorotannins may be a constituent of the cell walls. The group Oomycetes, also known as water molds, are saprotrophic plant pathogens like fungi. Until recently they were widely believed to be fungi, but structural and molecular evidence has led to their reclassification as heterokonts, related to autotrophic brown algae and diatoms. Unlike fungi, oomycetes typically possess cell walls of cellulose and glucans rather than chitin, although some genera (such as "Achlya" and "Saprolegnia") do have chitin in their walls. The fraction of cellulose in the walls is no more than 4
Sexual selection in fungi equivalent of male-male competition in plants and animals. They may also be choosy when being fertilized, the equivalent to female choice. Sexual selection in fungi aids in explaining certain characteristics including the high redundancy of pheromones in the B mating-type locus as well as strong pheromone signaling in yeasts. Pheromone signaling is used within fungi to either attract a mate or to assess the quality of that gamete; and tends to be more effective when occurring over small distances. Female gametes are typically the ones responsibly for producing pheromones in order to attract a mate. However, pheromones can also be