Life Cycles of Fungi

Vocabulary flashcards covering the sexual and asexual life cycles of fungi, plant and animal reproductive patterns, taxonomic nomenclature rules, and specific fungal life cycle categories (haplobiontic A, haplobiontic B, and diplobiontic).

Telemorph

The form or morph representing the sexual state (also referred to as the perfect state) of a fungus.

Anamorph

The form or morph representing the asexual state (also referred to as the imperfect state) of a fungus.

Holomorph

The complete fungus encompassing both its sexual (telemorph) and asexual (anamorph) states, such as Talaromyces vermiculatus bearing both ascospores and conidia.

ICBN

The International Code of Botanical Nomenclature, which permits telemorph and anamorph states to be treated as separate species, giving precedence to the telemorph name when both are identified as states of the same fungus.

Talaromyces vermiculatus

The holomorph and telemorph name of a fungus that produces ascospores and takes precedence over its anamorph name (Penicillium vermiculatum).

Penicillium vermiculatum

The specific name applied strictly to the anamorph (asexual/imperfect state) of the fungus Talaromyces vermiculatus.

Meiosis

The alternating process in sexual reproduction where the chromosome number is reduced from diploid to haploid (from $2n$ to $n$).

Fertilization

The process in sexual reproduction where the nuclei of two gametes fuse, raising the chromosome number from haploid to diploid ($n + n = 2n$).

Gametophyte Generation

The multicellular haploid ($n$) phase in plants that begins with a spore produced by meiosis and subsequently generates gametes by mitosis.

Sporophyte Generation

The multicellular diploid ($2n$) phase in plants that begins with a zygote and contains cells that eventually undergo meiosis to produce spores.

Haplobiontic

Characterized by having a single generation in the life cycle, meaning the organism possesses only one type of thallus.

Haplobiontic A Life Cycle

A fungal life cycle where nuclear fusion is followed immediately by meiosis (nuclear sequence: nuclear fusion – meiosis – mitosis), resulting in a haploid ($n$) thallus.

Haplobiontic B Life Cycle

A fungal life cycle where nuclear fusion is followed by mitosis (nuclear sequence: nuclear fusion – mitosis – meiosis), producing a diploid ($2n$) vegetative thallus as seen in Oomycetes and yeasts.

Basidium

A specialized cell in many basidiomycetes in which meiosis occurs, representing a modified haplobiontic B life cycle.

Diplobiontic Life Cycle

A life cycle characterized by alternation of generations between distinct, free-living haploid ($n$) and diploid ($2n$) thalli, following the nuclear sequence: fusion – mitosis – meiosis – mitosis.

Blastocladiales

An order of fungi in which alternation of generations (a diplobiontic life cycle) is common, contrasting with most other fungal groups where it is rare.