2 I. What Are Fungi? Fungi - eukaryotic heterotrophs that have cell walls1. Cell walls contain chitin, a complex carbohydrate
3 B. Depend on other organisms for food 1. Digest food outside of their bodies2. Then food is absorbed3.Some absorb nutrients from decaying matter in the soilC. Other fungi are parasites1. Absorb nutrients from hosts
4 II. Structure and Function of Fungi Except for yeasts, fungi are multicellularHyphae - thin filaments1. Each hypha is only one cell thick
5 2. In some fungi, cross. walls divide. hyphae into cells. with 1 or 2 2. In some fungi, cross walls divide hyphae into cells with 1 or 2 nuclei3. In the cross walls, there are openings through which the cytoplasm and nuclei can moveMost fungi are made up of filaments called hyphae. In some fungi, the hyphae are divided by cross walls.Fig Pg Most fungi are made up of filaments called hyphae. In some fungi, the hyphae are divided by cross walls.
6 4. Some hyphae lack cross walls and contain many nuclei Most fungi are made up of filaments called hyphae. In some fungi, the hyphae lack cross walls and contain many nuclei.
7 C. Fungus Structure The bodies of multicellular fungi are composed of many hyphae tangled together into a thick mass called a myceliumThe mycelium permits a large surface area to come in contact with the food source through which it grows
8 3. A mushroom is the fruiting body of a fungus 4. A fruiting body – reproductive structure
9 Structure of a Typical Fungus Fruiting bodyHyphaeThe body of a mushroom is part of a mycelium formed from many tangled hyphae. The major portion of the mycelium grows below ground. The visible portion of the mycelium is the reproductive structure, or fruiting body, of the mushroom.MyceliumFig Pg The body of a mushroom is part of a mycelium formed from many tangled hyphae. The major portion of the mycelium grows below ground. The visible portion of the mycelium is the reproductive structure, or fruiting body, of the mushroom.
10 III. Reproduction in Fungi Most fungi reproduce both asexually and sexually
11 Asexual reproduction1. Hyphae break off and begin to grow2. Some produce sporesa. Scatter and growb. Produced in sporangia located at tips of specialized hyphae called sporangiophores
12 B. Sexual reproduction1. Two mating typesa. “+” (plus)b. “–” (minus)2. Meet and fusea. “+” and “–” nuclei in one cell3. Form a diploid zygote nucleusa. Enters meiosisb. Produces haploid spores – capable of growing into new organisms
13 IV. How Fungi Spread A. Dry spores - scatter easily in the wind 1. Need proper environment (temperature, moisture, and food) so they can growB. Other fungi are specialized to lure animals1. Disperse spores over long distancesPuffball
14 Fungi are eukaryotic heterotrophs with cell walls made of chitin. 21–1 The Kingdom FungiFungi are eukaryotic heterotrophs with cell walls made of chitin.Chitin is a complex carbohydrate. Fungi do not ingest their food.Instead, fungi digest food outside their bodies and then absorb it.All fungi except for yeasts are multicellular.Multicellular fungi are made up of thin filaments called hyphae (singular: hypha).Each hypha is only one cell thick.The bodies of multicellular fungi are made of hyphae tangled together into a thick mass called a mycelium.The mycelium allows a large surface area to come into contact with the food source through which the fungi grow.The fruiting body of a fungus is a reproductive structuregrowing from the mycelium in the soil beneath it. In a mushroom,the fruiting body is the aboveground part of the mushroom.
15 Most fungi reproduce both asexually and sexually Most fungi reproduce both asexually and sexually. • Asexual reproduction can occur when cells or hyphae break off and begin to grow on their own. Some fungi also make spores. In some fungi, spores are formed in structures called sporangia. Sporangia are found at the tips of hyphae called sporangiophores. • Sexual reproduction in fungi usually involves two different mating types. One type is called “” (plus), and the other is called “” (minus). When the hyphae of a “” fungus meets the hyphae of a “” fungus, they fuse together in the same cell. After a period of growth and development, the nuclei form a diploid zygote. The diploid zygote enters meiosis, and produces haploid spores.
16 Spores of fungi exist in almost every environment Spores of fungi exist in almost every environment. Many fungi produce dry, almost weightless spores that are easily scattered by wind. For these spores to grow, they must land in a favorable environment. Temperature, moisture, and food conditions must be in the right combination. Most spores, therefore, do not grow into mature organisms. In fact, the probability that a spore will germinate and grow into a mature fungus can be less than one in a billion.