Fungi Flashcards
Heterotrophs
Don’t do photosynthesis (autotrophic plants) or make their own food. They secrete digestive enzymes and absorb the nutrients.
Fungi
100,000 species identified. May be 1.5 million species.
They’re decomposers. They break down organic materials and recycle nutrients.
Hyphae
Basic fungal cell with a tubular cell wall strengthened with chitin, and a plasma membrane filled cytoplasm.
Mycelium
A mat of hyphae
Mycorrhizal fungi
Hyphae
Are used to kill prey. It can close around a nematode worm in 4 seconds.
Mycorrhizal fungi
Haustoria
Penetrate the worm, digest it, and absorbs the nutrients.
specialized hyphae
Mycorrhizal fungi
Some types of Mycorrhizal fungi increase the delivery of phosphate and minerals to plants.
I.e. Ectomycorrhizal fungi growing on root surfaces.
I.e. Arbuscular mycorrhizal fungi grows around and into root of some plants.
Fungi reproduce…
Sexually and asexually
Sexual reproduction:
Most hyphae cells are haploid (n). Separate mycelia produce either + or - pheromones, like male and female.
Sexual reproduction:
Plasmogamy
When + and - are near each other, they grow toward each other. When they meet,the cells fuse. Called plasmogamy.
Sexual reproduction:
Heterokaryon
The cells don’t fuse right away. Heterokaryon - a hyphae with two genetically different nuclei. Crossing over, or exchange of genetic material can happen.
Sexual reproduction:
Dikaryotic
Haploid nuclei pair off 2 to a cell. The hyphae divide, but retain 2 separate nuclei. Called dikaryotic bc they’re not true diploid cells.
Sexual reproduction:
Haploid cells
Generally egg and sperm. One set of chromosomes.
Sexual reproduction:
Diploid cells
Cells produced when an egg and sperm combine. I.e. General body cells
Sexual reproduction:
Karyogamy
The haploid nuclei fuse forming a diploid cell, called a zygote. Meiosis occurs forming spores, which form new haploid but genetically different hyphae.
