120 likes | 145 Views
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.
E N D
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- • 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.