Kingdom Fungi

Chapter 21, page 527

• http://www.youtube.com/watch?v=4NO299do_l4

Homework

• Page 529:– Question 1, 2, 3, 4, and 5

Kingdom Fungi (over 100 000 species)

Characteristics of fungi:1. Eukaryotic2. Multicellular (except for yeast)3. Heterotrophic :

a. lack chlorophyllb. digest food outside the by secreting

digestive enzymes into the surrounding area, breaking food molecules into smaller molecules which can be absorbed. They do this in one of 3

ways.

How Fungi Obtain Food i. Saprophyte:

- Fungus uses dead or dying organisms for its food source thereby recycling matter into its original elements.

How Fungi Obtain Food

ii. Parasite:- absorbs food

from a live host’s cell

- ex.Yeast infectionAthlete’s footRingworm

ringworm

How Fungi Obtain Food

iii. Symbiotic relationships in which two or more living organisms benefit.

Ex. Lichen which is actually a fungus and a photosynthetic organism (plant or bacteria).

The fungus gives an ability to retain moisture and protection from the elements. The photosynthetic organism gives food.

Kingdom Fungi continued

4. Fungi are made up of thin filaments called hyphae. Each hypha is only one cell thick.

Copyright Pearson Prentice Hall

Structure and Function of Fungi• In some fungi,

cross walls divide hyphae into cells with 1 or 2 nuclei.

• In the cross walls, there are openings through which the cytoplasm and nuclei can move.

Copyright Pearson Prentice Hall

Structure and Function of Fungi• Some hyphae don’t have cross walls and

contain many nuclei.

Copyright Pearson Prentice Hall

• Fungus Structure

– The bodies of multicellular fungi are composed of many hyphae tangled together into a thick mass called a mycelium.

– The mycelium allows a large surface area to come in contact with the food source.

Copyright Pearson Prentice Hall

• Structure of a Typical Fungus

Hyphae

Fruiting body

Mycelium

• A fruiting body is a reproductive structure growing from the mycelium in the soil beneath it.

Kingdom Fungi continued5. Cell walls of Fungi are made of chitin, a

complex carbohydrate.(Same substance in lobster shells.)

6. Most fungi reproduce sexually and asexually.

Asexual Reproduction

• Asexual reproduction takes place wheni. cells divide (binary fission)

ii. cells or hyphae break off from a fungus and begin to grow on their own (fragmentation). Ex. Athlete’s foot

iii. a part of the cell pinches off to form new cells (budding) Ex. yeast

iv. spores are produced and then scatter and grow. Ex. most fungi

Conidia and conidiophore

Sexual reproduction involves• 2 different mating types, “+” or “-”.

• When hyphae of opposite mating types meet, they start the process of sexual reproduction by fusing, bringing plus and minus nuclei together in the same cell.

• After a period of growth, these nuclei form a diploid zygote.

• The zygote enters meiosis and produces haploid spores.

• These spores are capable of growing into new organisms.

Fungi are classified by their reproductive structures

• We will study four phylum. All end in “mycota”.

Zygomycota (common mold)Basidiomycota (mushroom)Ascomycota (sac fungi)Deuteromycota (imperfect fungi)

Reproduction

• crash course fungi

• http://www.youtube.com/watch?v=qDwgSWDqKoQ&feature=related

• Homework Page 529:– Question 1, 2, 3, 4, and 5

Phylum Zygomycota (called Zygomycetes)

• common mold• Grows on cheese,

bread, meat, fruit• Have life cycles that

include a zygospore (resting spore that contains zygotes formed during the sexual phase of the mold’s life cycle.)

• Generally lack cross walls in their hyphae, except for their reproductive hyphae.

• Diagram of the life cycle of zygomycetes (both asexual and sexual).

Mold Time lapse

• http://www.youtube.com/watch?feature=fvwp&NR=1&v=JsQHWj2RfXg

Life Cycle

Phylum Ascomycota (page 532)

• Named for the ascus, a reproductive structure that contains spores.

• Over 30 000 species (largest Phylum of Kingdom Fungi)

• Includes yeast

• Vocabulary:– Conidia (singular conidium) spores– Conidiophores (hyphae on which the conidia grow

at the very tip)– Ascus (plural asci) Forms within the fruiting body

Within the ascus, two nuclei of different mating types fuse to form a diploid zygote (2N).

Phylum Ascomycota (page 532)

Phylum Basidiomycota (page 534)

• Include mushrooms, shelf fungi, puffballs, earthstars, and plant rust.

• Often called club fungi because many of their fruiting bodies look like clubs.

http://www.youtube.com/watch?v=qDwgSWDqKoQ&feature=related

Phylum Basidiomycota

• The structure that bears the spores is called a basidium (plural basidia).

• Basidia are found on the gills.

Life cycle of a Basidiomycete

Phylum Deuteromycota (page 536)

• Scientists don’t know how these fungi reproduce as they have never been able to observe their life cycles.

• Also called “imperfect fungi” because our understanding of their life cycles is imperfect.

• Includes Penicilloum notatum.

Review

• Page 545: 1 to 5 7 to 10 12, 13, 15, 16, 17, 18, 22, 23

Answer these questions for Thursday.