Kingdom Fungi

Question 1

_____________ leads us to some of the first terrestrial organisms on the planet,

Answer 1

Kingdom fungi

Question 2

Data indicate that _____________ began colonizing terrestrial environments at about the same time.

Answer 2

plants and fungi

Question 3

Fungi differ from our other groups in that they are primarily _____________, sustaining themselves on_____________ through ________. Some fungi are parasitic on living organisms, but most feed on dead and decaying matter.

Answer 3

Fungi differ from our other groups in that they are primarily decomposers, sustaining themselves on decaying matter through absorption via their hyphae. Some fungi are parasitic on living organisms, but most feed on dead and decaying matter.

Question 4

Believe it or not, the largest living organism on the planet is thought to be a _______. This massive mass of _______ covers many acres.

What we notice are their fruiting bodies that only appear for reproductive purposes.

Answer 4

fungus, hyphae

Question 5

Many fungi, like ______, are single-celled and hardly noticeable but very necessary to make bread and brew beer, or problematic when they infect humans and cause yeast infections.

Answer 5

yeasts

Question 6

Basic parts and functions of a multicellular fungi

Why don’t we see well defined cell walls?

Answer 6

The cell walls of fungi are strengthened by a polysaccharide called chitin. Chitin also helps aid absorption and helps them avoid rupture in hypotonic environments.

The basic structure of a fungus is the hyphae. The hyphae compose the mycelium and even extend into the fruiting body. The fruiting body will produce spores.

Hyphae are often just one big multinucleate cell in many species (coenocytic). In other species, the hyphae may be septate or divided. Even in septate hyphae, there is tremendous flow of cytoplasm. A fungus needs maximum surface area to effectively absorb nutrients. Then, those nutrients need to easily flow to the entire organism. This is why we don’t see well-defined cells.

Question 7

Types of Hyphae and their characteristics

Answer 7

Hyphae are often just one big multinucleate cell in many species (coenocytic). In other species, the hyphae may be septate or divided. Even in septate hyphae, there is tremendous flow of cytoplasm. A fungus needs maximum surface area to effectively absorb nutrients. Then, those nutrients need to easily flow to the entire organism. This is why we don’t see well-defined cells.

Question 8

Specialization of hyphae

Answer 8

Some hyphae trap and hold on to organisms until they die, then absorb them. Other hyphae form arbuscules that enter into living cells and acquire nutrients. Probably one of the most important aspects of fungi and hyphae is ectomycorrhizal fungi. These fungi exchange nutrients with the roots of plants and effectively increase the absorption area of plants. This mutualistic relationship helps both fungus and plant, and the plant most likely would not survive without the association.

Question 9

Fungi reproduction

Answer 9

Fungi have the ability to reproduce asexually (no genetic recombination) or sexually. Most fungi produce large numbers of spores. In fungi spores can arise from asexual processes or sexual processes.

Question 10

Plasmogamy

Answer 10

Plasmogamy is the fusion of cytoplasm from two parent fungi. It is indicated by the fusion of hyphae without fusion of nuclei.

Question 11

Karyogamy

Answer 11

Karyogamy is the fusion of nuclei from two parent fungi. It results in the formation of a diploid zygote.

Question 12

Heterokaryotic

Answer 12

It is a cell that contains two or more genetically different nuclei in a cytoplasm. Has two or More nuclei. It is not unique to fungi.

Question 13

Dikaryotic

Answer 13

It is a fungal cell that has two genetically different nuclei in a cytoplasm and has two different nuclei.These nuclei are separated by a septum.

Question 14

Ploidy Level of Spores:

Answer 14

Spores are predominantly haploid (n).

Question 15

Spores via Asexual vs. Sexual Reproduction:

Answer 15

Spores can be produced via both asexual and sexual reproduction.
In asexual reproduction, spores are produced directly from the parent organism without fusion of gametes. These spores are genetically identical to the parent.
In sexual reproduction, spores are produced through meiosis following the fusion of haploid nuclei from two parent organisms. These spores are genetically diverse and undergo genetic recombination

Question 16

Is a fungus predominantly haploid or diploid? (How does it spend most of its life cycle?

Answer 16

haploid dominant life cycle

Question 17

Fungi arise from the ____________ and have a common flagellated ancestor.

Answer 17

opisthokonts

Question 18

Fungi are a ________ group and moved to land about 470 million years ago.

Answer 18

monophyletic

Question 19

5 major fungal groups

Answer 19

Though fungal groups are better aligned than Protist groups there are still lots of questions; therefore, we recognize 5 major groups: Chytrids (water molds), Zygomycetes (form zygospores), Glomeromycetes (arbuscular mycorrhizae), Ascomycetes (sac fungi that form ascocarps), and Basidiomycetes (mushrooms).

Question 20

Zygomycetes (now called Mucoromycetes)

Answer 20

Zygomycetes are commonly referred to as bread molds, and that’s exactly where you will likely find them in your environment or perhaps colonizing your shower. All zygomycetes form zygospores inside zygosporangium. When conditions are favorable (on your bread or in your shower), they generally go through asexual reproduction and form lots of haploid spores (that’s the black or blue stuff you see). But when conditions get rough, they reproduce sexually. The zygosporangia is very resilient and can withstand adverse conditions. When conditions improve, the zygosporangia will germinate, undergo karyogamy, undergo meiosis, form a sporangium and produce haploid spores.

Question 21

Ascomycetes

Answer 21

Ascomycetes can be found in many habitats and may be unicellular (yeasts) or multicellular (morels). They are defined by producing ascospores in asci. Since asci look like little sacks, they are often called sac fungi. The fruiting body of the ascomycete is the ascocarp, which contains the asci.

In Ascomycetes, asexual reproduction results in the production of conidiophores and conidia (asexual spores).

Question 22

Basidiomycetes

Answer 22

This group comprises mushrooms, puffballs, shelf fungi, oyster fungi, etc. Humans commonly consume these, but some are very VERY toxic. Amanita phalloides mushrooms (the “Death Cap”) are thought to be the most toxic and sadly look like edible straw mushrooms. 50% of people who consume them die. The other 50% are extremely ill. The mushroom that Smurfs “live” in is the species Amanita muscaria and, though only mildly toxic, is a significant hallucinogen. So yes, the Smurfs lived in shrooms!!! Think about that now as an adult.

Basidiomycetes are noted by the basidiocarp, gills, basidia, and basidiospore. Another unusual feature of the basidiomycete is that they spend most of their life cycle as a dikaryotic (n+n) mycelium.

Question 23

Ecological Niches of Fungi

Answer 23

Decomposers - Fungi decompose basic carbohydrates and proteins and decompose those that most organisms cannot, like cellulose, lignin, and chitin.

Mutualists - Fungi show mutualistic relationships with all other kingdoms of organisms and some prokaryotes. Mycorrhizal associations are of extreme importance to other producers.

Symbionts - Some Fungi are hosts to a very interesting symbiotic relationship with green algae and cyanobacteria. This association is so tight that neither organism can live without the other. This is so much so that we name these Lichen and study them as solitary organisms.

Question 24

Lichens

Answer 24

Lichens - most lichens are ascomycetes, but we do know of some basidiomycetes and at least one glomeromycete lichen.

Forms: fruticose (shrublike), crustose, foliose (like foliage)

Question 25

Parasites

Answer 25

Fungal infection is problematic in various organisms, including humans. Fungus does millions of dollars worth of damage to crops each year. Fungus is currently decimating amphibian populations and is responsible for White Nose in Eastern Bats.