Chapter 21: Fungi Biology- Kirby

21-1: The Kingdom Fungi Fungi are eukaryotic heterotrophs that have cell walls. These cell walls are made of chitin. Fungi digest food outside their bodies and then absorb the nutrients. Some fungi absorb nutrients from decaying matter, while others are parasites that absorb nutrients from their host’s body.

21-1: The Kingdom Fungi Structure & Function of Fungi: Multicellular fungi are composed of thin filaments called hyphae. Each hypha is one cell thick, has many nuclei, and sometimes interior walls. When many hyphae are tangled togather, they form a thick mass called a mycelium.

21-1: The Kingdom Fungi The mushroom you see is the fruiting body (reproductive structure growing from the mycelium in the soil) of the fungus. Fairy Rings- Clusters of mushrooms are often part of the same mycelium. As time passes, the mushrooms will only grow on the edge of the mycelium producing a ring of mushrooms.

21-1: The Kingdom Fungi Reproduction in Fungi: Asexual- Sexual- 1. hyphae break off and grow independently. 2. produce spores that spread their genes. Sexual- The gametes are the same size, so they are referred to as a + and -. The + and – meet and fuse together producing a diploid zygote.

21-1: The Kingdom Fungi How Fungi spread: Fungi produce dry lightweight spores that scatter easily. Many spores are often spread by other organisms which carry them. These spores need the right temperature, moisture, and food to survive.

21-2: Classification of Fungi Fungi are classified according to their structure and reproduction method. There are 4 main groups of fungi: Common mold: Zygomycota Sac fungi: Ascomycota Club fungi: Basidiomycota Imperfect fungi: Deuteromycota

21-2: Classification of Fungi Common Molds: Grows on meat, cheese, and bread. Sexual reproduction 2 kinds of hyphae: Rhizoids- rootlike hyphae that penetrate the bread’s surface. Stolons- stemlike hyphae that run along the surface of the bread.

21-2: Classification of Fungi Sac fungi: Have a cuplike shape. Asexual & sexual reproduction. Ascus- reproductive structure within the fruiting body. Yeasts- unicellular fungi- Budding- asexual process of dividing yeast cells.

21-2: Classification of Fungi Club fungi: Have a reproductive structure called the basidium that looks like a club. Most complex life cycle of the fungi. Very diverse group of fungi. Imperfect fungi: Fungi that do not have a sexual phase of their life cycle.

21-3: Ecology of Fungi In order for fungi to get food, their mycelia can grow very rapidly into tissues and cells of other organisms. Fungi help maintain equilibrium in ecosystems because they break down bodies and wastes of other organisms and recycle the nutrients. Most secrete an enzyme to break down matter.

21-3: Ecology of Fungi Parasitic fungi cause plant, animal, and human diseases. Some fungi form symbiotic relationships where they both benefit (mutualism). Example- Lichens- relationship between a fungus and a photosynthetic organism. Mycorrhizae- relationship between a fungus and a plant.