KINGDOM FUNGI

1

INTRODUCTION TO FUNGI

Mushrooms, toadstools, mildews, yeasts and moulds are all members of this kingdom.

Some unicellular fungi, but most are multicellular.

Have similarities to both plants and animals

Like animals because they are heterotrophs

Like plants because they have a cell wall

2

FUNGI MORPHOLOGYMulticellular species have ‘bodies’ made up of hyphae, a network of fine filaments

Hyphae aren’t as visible in mushrooms because they are so densely packed together in a tight mass

The mushroom part you see is only one part of the complex fungus.

The majority of the organism is contained underground in the form of a loose branching network of hyphae called mycelium

3

4

MORPHOLOGYSome species have hyphae (hypha) that are divided into cells by cross walls called septa (septum)Each individual cell has one or more nucleiSepta are porous and allow for the movement of cytoplasm to flow through the hyphae from cell to cellIn cells without septa, each hypha looks like one big cell with many nuclei and undivided cytoplasm.The cell walls of fungi are made of chitin, which is also found in the exoskeletons of insects.

5

FEEDING

The majority are saprotrophs, which means they break down decaying matter and play a big role in the recycling of nutrients.

As hyphae grow across a food source, they release digestive enzymes that break down large organic molecules into smaller organic molecules

6

FEEDING

This is called extracellular digestion because it happens OUTSIDE the body

The more extensive the mycelium the more space for absorbing nutrients

7

PARASITIC FUNGISome fungi are parasites and can cause diseases such as athlete’s foot and ringworm.

They are specialized and produce hyphae called haustoria which penetrates host’s cells without killing them (Dutch Elm Disease)

Cordyceps myrmecophila (ant-loving) invades and kills ants by absorbing the ant’s internal cavity through its growing hyphae.

8

SYMBIOTIC FUNGI

Many fungus live in symbiotic relationships with plants or animals

An example is that most trees have mycorrhiza in close contact with their roots.

The hyphae of these fungi enter the cells of the roots and help provide the roots with nutrients. The fungus also improves air and water flow through the soil. The fungus benefits by absorbing organic nutrients from the plant.

9

FUNGAL REPRODUCTION

Most fungi have both asexual and sexual methods of reproduction

The simplest asexual way is fragmentation, in which pieces of the hyphae are broken off and grow into new mycelia. This happens if something breaks the mycelium, like a gardener, for instance…

10

FUNGAL REPRODUCTIONThe majority of fungi live on land and therefore produce spores, which are windblown reproductive cells that help the fungi disperse to new locations.The spores are produced in great number to help increase the chances of dispersal and survival.Spores can be sexual or asexual depending on how they are producedA puffball can produce as many as one trillion spores!

11

CLASSIFYING FUNGI

Original ancestors of fungi are not known. They may have evolved separately from more than one origin.

Four subgroups…

12

FOUR SUBGROUPS:

1) Zygospore Fungi (Zygomycotes)

2) Club Fungi (Basidiomycotes)

3) Sac Fungi (Ascomycotes)

4) Imperfect Fungi (Deuteromycotes)

Part of your homework in addition to questions is to create a chart or concept map to compare these four subgroups of Fungi!

13

14

TED talk on Fungi

http://videos.howstuffworks.com/ted-conferences/7617-fun-with-fungi-video.htm

15