CHAPTER 11 Essay

Submitted By ezmersgirl
Words: 680
Pages: 3

1. Identify 6 basic shaped of prokaryotic cells. (p.316)
a. Coccus
b. Coccobasillus
c. Bacillus
d. Vibrio
e. Spirillum
f. Spirochete
g. Pleomorphic
2. What are the three common types of reproduction in prokaryotes? (p.317)
a. Binary fission
b. Snapping division
c. Budding
3. How is budding different from binary fission? (p.317)
a. Budding – In prokaryotes and yeasts, reproductive process in which an outgrowth of the parent cell receives a copy of the genetic material, enlarges, and detaches.
b. Binary Fission – The most common method of asexual reproduction of prokaryotes, in which the parental cell disappears with the formation of progeny
4. Draw and label arrangements in cocci and bacilli. (p.319)
5. A student was memorizing the arrangements of bacteria and noticed that there are more arrangements for cocci than for bacilli. Why might this be so? (p.318)
a. Cocci can divide in multiple planes, whereas Bacillus only divide transversely across their long axis.
6. Why are people concerned about endospores and endospore forming bacteria? (p.317)
a. Food processors, health care professionals, and governments are concerned about endospore formation because endospores can resist out attempts to kill them and because many endospore-forming bacteria produce deadly toxins that cause fatal diseases, such as anthrax, tetanus, and gangrene.
7. What is the most authoritative reference in modern prokaryotic systematics and what information do you find there? (p.319)
a. Bergey’s Manual of Systematic Bacteriology, which classifies prokaryotes into 26 phyla – 2 in Archaea and 24 in bacteria.
8. What are the common features of microbes in the domain Archaea?
a. Archaea lack true peptidoglycan in their cell walls.
b. Their cytoplasmic membrane lipids have branched or ring-form hydrocarbon chains, whereas bacterial membrane lipids have straight chains.
c. The initial amino acid in their polypeptide chains, coded by the AUG start codon, is methionine.
9. What are Extremophiles, Thermophiles, Halophiles, Methanogens? (p.321-322)
a. Extremophiles – microbes that require what humans consider to be extreme conditions of temperature, pH, and/or salinity to survive.
b. Thermophiles – prokaryotes whose DNA, RNA, cytoplasmic membranes, and proteins do not function properly at temperatures lower than about 45°C.
c. Halophiles – organisms that inhabit extremely saline habitats, such as the Dead Sea, the Great Salt Lake, and solar evaporation ponds used to concentrate sald for use in seasoning and for the production of fertilizer.
d. Methanogens – obligate anaerobes that convert CO2, H2, and organic acids into methane gas (CH4).
10. What are the roles played by methanogens in the environment? (p.322)
a. Methanogens play significant roles in the environments by converting organic wastes in pong, lake, and ocean sediments into methane.