Honors Biology

Module 4

Kingdom Fungi

October 1, 2015

Class Challenge

Who can do the most sit-ups in one minute!?!

Next week’s class challenge

Who can grow the most unique mold? Everyone has to participate in this !!!

Colorful

Prolific

What other categories???

Questions from this week’s homework

Question 1What are these pictures an example of ?

Questions 2 - 4

Members of phylum Pyrrophyta are often

referred to as _________________. They

have two ____________. One species in

this phylum, Gymnodinium brevis, have

blooms that are called ____________.

Question 5

5. What is Red Tide?

6. What are the large deposits of diatoms called?

7. List two uses of these deposits?

Question 1What are these pictures an example of ?

DIATOMS

Questions 2 - 4

Members of phylum Pyrrophyta are often

referred to as DINOFLAGLETTES.

They have two FLAGELLA. One

species in this phylum, Gymnodinium brevis,

have blooms that are called RED TIDE.

What is Red Tide?

5. Red tide is an algae bloom of dinoflagellates, which belong to phylum Pyrrophyta.

6. What are the large deposits of diatoms called?

Diatomaceous earth

7. List two uses of these deposits?

Abrasives and filters

Kingdom Fungi

Characteristics of Fungus

Although mushrooms are the most common fungi, there are many other kinds as well. 

Some fungi are pathogenic (disease-causing), but there are also helpful fungi:  some fungi are used in making cheese, others are used in baking, and even some in medicine.

Fungus

Most fungi are multicellular; a few are single-celled.  But whether multicellular or unicellular, their cells are all eukaryotes (each cell having membrane-bound organelles, each organelle performing a particular job). 

Their cells usually have many nuclei.

Kingdom FungiMost of the organisms in this kingdom

are heterotrophs (can't make their own food). Some of these heterotrophic fungi are parasitic (feed on living matter), but most are saprophytic(feed on dead matter). 

The saprophytic fungi are decomposers that promote the decay of once-living matter.  Otherwise, leaves would pile up each fall year after year, not to mention dead animals, and other things that decompose.

Kingdom Fungi

In a single autumn, the average elm tree will drop as much as 400 pounds of leaves on the ground. If it were not for fungi and other decomposers, those leaves would continue to pile up until the tree choked on its own dead leaves in just a few seasons.

Because of decomposers, the leaves will be broken down into chemicals that can then be re-used by the tree and other organisms in creation.

Kingdom Fungi

Saprophytic or parasitic, they both digest their food outside of their bodies. 

They secrete a chemical onto the food that digests the food before it is ingested (eaten). 

The digested food is then absorbed into the cell of the fungus.

Extracellular (outside the cell) digestion can be beneficial to other organisms that can often absorb some of the nutrients before the fungus has a chance to absorb them.

General characteristics of Fungi

Saprophytic: Feeds on remains of dead organisms.

Parasitic: Feeds on living host. Not as common.

Extracellular digestion: Digest their food outside of their body.

Spore reproduction: All produce spores for reproduction.

Mycelium: The part of the fungus responsible for extracellular digestion and absorption of the digested food.

Hypha: A filament of fungal cells.

General Structure of a Mushroom

See figure 4.1 (page 98)

• The general structure of a mushroom is easy to see. 

• There is the cap, which has the gills underneath (where the spores grow), and the stalk which is called the stipe.

• This is all called the fruiting body.

Mycelium

The mycelium isnot a root systemfor the mushroom.This is the main partof the mushroom. Each strand is a hypha.

Anatomy and Life Cycle

Hyphae

In some fungi, the hyphae are composed of individual cells separated from one another by cell walls, called Septate Hypha

(Figure 4.2)

Other fungi have hyphae that look like one big cell. There are no walls, and the nuclei are spread throughout the hypha. These are called Nonseptate hyphae.

Hypha

Even when a fungus is composed of septate hypha, its cells are not completely separated from one another because the pores in the cell walls allow cytoplasm to be passed between the cells.

This is a characteristic that is unique to kingdom Fungi.

Colonial protistans and monerans have cells that group together, but the cells do not exchange cytoplasm.

Plants and animals are multicellular, but their individual cells are completely separate; they do not exchange cytoplasm.

In kingdom Fungi, the cells are not completely separate.

Rhizoid hyphaIs a hypha that is imbedded in the material

on which the fungus grows. If the hypha is part of the mycelium, it is called a rhizoid hypha.

These are responsible for supporting the fungus and digesting the food. They are considered the main body of the fungus.

Other types of HyphaFigure 4.3

Aerial hypha: is not imbedded in the material upon which the fungus grows.

This hypha sticks up in the air. It can do one of three things: absorb oxygen from the air, produce spores or asexually reproduce to form new filaments.

If the hypha performs one of these jobs, it is further specified as either a sporophore or a stolon.

Sporophore: Specialized aerial hypha that produces spores.

Stolon: An aerial hypha that asexually reproduces to make more filaments.

Haustorium:

A hypha of a parasitic fungus that enters the host’s cells, absorbing nutrients directly from the cytoplasm.

ChitinMost fungi have cells walls that contain chitin.

This is a chemical that provides toughness and flexibility.

This chemical makes fungus hardy, it provides protection, like an armor.

It is the same chemical found in shells (exoskeletons) of arthropods (spiders, beetles, ants and lobsters).

Reproduction in Kingdom Fungi

• In addition to other various means of reproduction, the one means of reproduction all fungi have in common is by making spores.

• Most fungi are multicellular, and will grow a specialized structure for that particular type of fungus for the purpose of producing spores.

• For example, a mushroom has basidia on which their basidiospores form.  

•

• A spore print can be made by laying a mushroom cap on paper for several hours or overnight, covered by a bowl or jar to prevent air currents from disturbing the spores.

The sexual reproduction that usually occurs in fungi involves forming specialized structures called fruiting bodies.

Once the fruiting body is formed, it rises out of the mycelium and releases its spores.

The cap and stalk that we normally call a mushroom are just parts of the fruiting body of the mycelium of a fungus.

Although spore formation is the reproductive mode common to all fungi, most can also reproduce by other asexual means.

The hyphae cells in the mycelium can reproduce asexually, increasing the size of the mycelium

Also when the stolon is formed, the cells within it will reproduce asexually , lengthening the stolon.

After the stolon reaches a certain length, it will begin to reproduce into hyphae that will form the mycelium of a new fungus.

Mr. Anderson on Fungi

http://youtu.be/dj9m7Oc36wM

Experiment 4.1Phylum Basidiomycota

Object: To observe fungi that are readily found in most areas and to understand how members of phylum Basidiomycota grow and reproduce.

Homework

1. Prepare bread mold sample for next week’s experiment.

2. Continue reading Module 4 p. 109-120

3. Answer OYO questions 4.1 – 4.8.

4. Answer Study Guide questions: a-I and 2-13

5. Finish Lab 4.1 in lab book.

6. Class challenge: Bread mold beauty contest.

7. Label structure of a mushroom.