Rust (fungus) an autoecious fungus which can complete its life cycle on a single host species. Understanding the life cycles of rust fungi allows for proper disease management. There are definite patterns of relationship with host plant groups and the rust fungi that parasitize them. Some genera of rust fungi, especially "Puccinia" and "Uromyces", comprise species that are capable of parasitizing plants of many families. Other rust genera appear to be restricted to certain plant groups. Host restriction may, in heteroecious species, apply to both phases of life cycle or to only one phase. The fungi produce asexual spores which disperse by
Multicellular organism traits that are shared between distantly related lineages. The evolution of multicellularity could have occurred in a number of different ways, some of which are described below: This theory suggests that the first multicellular organisms occurred from symbiosis (cooperation) of different species of single-cell organisms, each with different roles. Over time these organisms would become so dependent on each other they would not be able to survive independently, eventually leading to the incorporation of their genomes into one multicellular organism. Each respective organism would become a separate lineage of differentiated cells within the newly created species. This kind of severely