Simplification of Biology: Fungi

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Fungi are a life form with over a million species.

Neither plant nor animal, it incorporates features of both.

Like plants, they are not very mobile; they are rooted to the earth and grow fruits to reproduce.
Like animals, they cannot make their carbon chains or organic compounds from the CO2 in the air and rely on plants for that, which can live on just bacteria, earth, water and sunshine.

Fungi live off of anything organic, animal or plant, living or dead. Sometimes fungi kill whoever they live on overtaking them like weeds choking a garden.

Fungi are nature's garbage men ensuring that dead organic matter decomposes to be recycled.

Fungi are abundant worldwide. They are found in every environment from deserts and areas with high salt concentrations to outer space with high ionizing radiation and deep under sea sediments under high pressures.

Fungi are categorized into 2 groups, single cell yeasts and multi celled molds.

Yeasts

Yeasts are single cell fungi. Like bacteria, they reproduce by making clones. The DNA of the cell is copied and the cell stretches or buds and breaks into 2 each with a copy of the DNA: There are only about 1,500 species of yeast. They favor neutral to acidic environments with pH as low as 5.

Yeast size can vary greatly depending on the species, typically measuring 3-4 micro-meters in diameter, although some yeast can reach over 40 micro-meters. As a comparison, the width of the period at the end of this sentence or of a human hair is 100 micro-meters.

Ancient peoples have used fungi as food sources, often unknowingly for millennia in the preparation of leavened bread and fermented juices. Yeasts is used as a leavening agent for bread. Yeast converts carbohydrates to carbon dioxide used to leaven breads. Yeasts also break up sugars into their constituent alcohols like wine from grape and beer from barley and wheat.

Many types of yeast are parasites on plants and animals sometimes killing the host.

Other yeasts like Candida can attack mouth and vagina cavities. While their presence is clearly visible, they themselves are too small to be seen.

Molds

While yeast are single cell organisms that reproduce asexually, molds are multi-celled organisms that reproduce sexually by 2 molds sharing and mixing their DNA in a way similar to copulation.

They produce genetically different copies that grow to extraordinary dimensions and ages as in the case of an example of Armillaria solidipes which extends over an area of more than 9 square km and is 9,000 years old.

Molds grow in multicellular filaments called hyphae, collectively called a mycelium. Hyphae are cylindrical, thread-like structures 2-10 micro-meters in diameter and up to several centimeters in length. They resemble microscopic roots and like roots can anchor to ground or tissue, penetrate it and branch and grow unnoticed underneath it. Molds use their under ground hyphae to exchange DNA and grow mushrooms above ground so that the spores can be dispersed.

Despite their size, molds only become noticeable when fruiting above the ground as mushrooms, or

when they are uncovered and seen as mildew or mold. Most grow in terrestrial environments, though several species live partly or solely in aquatic habitats, such as the fungus Ba- trachochytrium dendrobatidis, spends part of its life cycle like a sperm cell, searching, finding and penetrating an amphibian host.

Molds are ubiquitous in nature, and mold spores are a common component of household and workplace dust. However, when mold spores are present in large quantities, they can cause allergies and respiratory problems. Molds can thrive on many organic materials, including clothing, leather, paper, and the ceilings, walls and floors of homes or offices with poor moisture control. Molds need moisture and organic material to grow on even if it’s thinly smeared on ceramic tiles or plastic.

Like yeast is used to ferment sugars in fruits to make CO2 and alcohol, molds are used to ferment soybean and wheat mixture to make soybean paste and soy sauce. Molds break down the starch in rice, barley, and sweet potatoes, to make a high alcohol content drink called sake.

Many molds are parasites on plants and animals sometimes killing the host. Other molds can attack eyes, nails, hair, skin like in ringworm and between the toes like in athlete's foot. Many molds cause food spoilage and many are poisonous to humans.

Other times molds form partnerships called symbiosis with organisms as seen in lichens, algae and seaweed. Most plants depend on fungi for their uptake of inorganic compounds, such as nitrates and phosphates.

Several groups of ants cultivate fungi as their primary food source,

Penicillin protect organisms like man against certain bacteria.

Certain molds help man make types of cheeses like the blue colored Roquefort, with unique flavor and texture.

Some mushrooms give man hallucinations.

Certain fungi, in particular "white rot" fungi, helps nature by degrading insecticides, herbicides, coal tars, and heavy fuels and turn them into carbon dioxide, water, and basic elements. Despite their visible contributions, molds are normally not seen until they grow fruit called mushrooms.

Mushrooms

Identifying and eating mushrooms

Presence of juices upon breaking, bruising reactions, odors, tastes, shades of color, habitat, and season are all considered to identifying a mushroom.

The most definitive identifying feature is the spores, which are all unique to each species.

Edible mushrooms are a good source of vitamin D2 if they have been exposed to light. Like the meats they replace so well in cooking, they are a good source of B vitamins. They are high in the essential minerals selenium, copper and potassium, and have medicinal uses as traditional Chinese medicine.

Genera with mushrooms containing deadly toxins are the destroying angel (Amanita virosa) and the death cap (Amanita phalloides). They are the most common cause of deadly mushroom poisoning.

The sex lives of Mushrooms

Compared to the sex lives of yeasts who divide without sex and go their own way until they die, molds really have it romantic. Molds are either males or females. They eject spores that germinate like seeds under optimal conditions. They grow a root-like thread which spreads like a penis with sperms or like a vagina with eggs, searching for a mate.

When a germinating spore of a male finds, couples and mates with the germinating spore of a female, the 2 hyphae fuse together and DNA is exchanged giving birth to a cell that grows and divides like a fetus into a network called the mycelia.

Like a brain, mycelia grow in an underground network of single celled fibers that transmit signals. At the right conditions, they form spore bearing fruit called mushrooms that attract animals to spread their spores. About a billion spores are produced by each mushroom and they fall in a fine rain of powder from under the caps.

Depending on its genetic mixing, the mycelia eventually produce spore forming fruit called mushrooms that produce from their periphery either spores corresponding to sperms or spores corresponding to eggs.