Chapter 31
1. Fungi can have very complicated life cycles but the standard fungus life cycle includes a multicellular or colonial haploid stage. This stage is in the form of a fibrous mass called a mycelium and each of the fibers is called a hypha. Fungus life cycles also include the presence of genetically different mating strains. These look alike but the cells of the hypha. can tell them apart. What’s critical for mating is that unlike mating strains get together and their nuclei fuse to form the diploid zygote.
2. Species in this phylum reproduce sexually by forming spores on top of club-shaped structures called basidia. The club fungi are believed to be closely related to the sac fungi. Both groups have cells which are separated by septa and both have a dikaryotic phase in their life cycle; a phase with two haploid nuclei per cell. The septum of the club fungi is somewhat different from those of sac fungi and is referred to as a dolipore septum. The dolipore septum has a bagel-shaped pore in its center. Club fungi species reproduce sexually by forming spores on top of club-shaped structures called basidia. The club fungi are believed to be closely related to the sac fungi. This large group includes species that are known as mushrooms, toadstools, earthstars, stinkhorns, puffballs, jelly fungi, coral fungi, and many other interesting names. Some species, such as the rusts and smuts, cause disease in agricultural grains. Other species, such as the fly agaric, produce chemical hallucinogens and have been used by numerous cultures in their religious ceremonies.
The Essay on Bryophyte And Pteropyte Life Cycles A Comparecontrast
Although Bryophytes and Pterophytes are both plant divisions with a common ancestor, they have little in common. While Bryophytes (mosses) are generally nonvascular and very short in height, Pterophytes (ferns) are vascular plants that usually grow much taller than mosses. While the dominant generation in mosses is the gametophyte, ferns exhibit the sporophyte generation. The details of their ...
3. Fungi are saprotrophs meaning that they are decomposers. This makes them very important to the ecosystem as recyclers of dead material and waste matter. They and bacteria are the clean-up crew of Mother Nature. They dump digestive enzymes onto the food they are eating and then they absorb the digested meal through their cells.
4. Nutrition, Structural organization, Growth and reproduction
5. To acquire there nutrients fungi secrete hydrolytic enzymes and acids to decompose complex molecules into simpler ones that can be absorbed.
6. Fungi look for new food sources through extensions of hyphae that can grow up to a kilometer total per day. Parasitic fungi have haustoria which penetrate a host for nutrition.
7. Fungi have hyphae which make up the mycelium and are the underground part of the fungi. They are composed of chitin which is a nitrogen containing polysaccharide. The hyphae help to improve surface area which helps with absorption.
8. Karyogamy is the fusion of the nuclei in the cell. Plasmogamy is the fusion of cytoplasm in the cell, but not the nuclei.
