1. Plasma membrane acts as a selective barrier allowing nutrients to enter the cell and wastes to leave the cell.
  1. Peptidoglycan is the MOST common compound in the cell walls of gram-positive bacteria.
  1. Gram-positive bacteria should be very vulnerable to inhibition by penicillin because penicillin is an antibiotic that inhibits enzymes from catalyzing the synthesis of peptidoglycan.
  1. Bacteria rarely thrive in high sugar content foods, even if the food containers are left open, because the bacteria undergo death by plasmolysis.
  1. Correct order of how a predatory bacterium such as Bdellovibrio bacteriophorus may drill into its prey’s cytoplasm.
  2. Capsule
  3. Membrane composed of lipopolysaccharides
  4. Peptidoglycan
  5. Membrane composed of phospholipids
  1. If a bacterium possesses antibiotic resistance and the potential to persist through very adverse conditions such as freezing temperatures, where should the DNA be located? The nucleoid region, endospore, and/or plasmids.
  1. A complex “motor” is embedded in the cell wall and plasma membrane of the typical prokaryotic flagellum.
  1. The prokaryotic chromosome is not contained within a nucleus, but, rather is found at the nucleoid region.
  1. The following statements are in relation to a gram-positive prokaryotic cell.
  • The cell wall is composed almost entirely of peptidoglycan.
  • Flagellum requires ATP to function, and permits some species to respond to taxes.
  • A capsule is not present in all bacteria, this cell covering enables cells that possess it to resist the defenses of host organisms.
  • The endospore is not present in all bacteria. This structure enables those that possess it to germinate after exposure to hard conditions.
  • The sex pilus is a structure that permits conjugation.
  1. The cell wall is an important source of endotoxins in gram-negative species.
  2. Mutation is a primary source of variation I prokaryote populations.
  1. Prokaryotes divide by binary fission, without mitosis or meiosis.
  1. Bacteria can grow and genetically change quickly; this can be graphed. A period of time depicting a high rate of genetic change may have a steep slope on a line graph.
  1. To increase the number of bacteria, and thus genetic variation through possible beneficial mutations, binary fission must take place.
  1. Chemotroph: an organism that obtains its energy from chemicals.
  1. Heterotroph & Chemotroph: A prokaryote that obtains both energy and carbon as it decomposes dead organisms. Both can also obtain carbon and energy by ingesting prey.
  1. Parasitic chemoheterotrophs are responsible for many human diseases.
  1. Cyanobacteria are examples of photoautotrophs.
  1. Photoautotrophs use light energy to synthesize organic compounds from CO2.
  2. Chemoautotrophs obtain energy by oxidizing inorganic substances; energy that is used, in part, to fix CO2.
  1. Photoheterotrophs use light energy to generate ATP, but they do not release oxygen.
  1. Photoautotrophs are responsible for high levels of O2 in the atmosphere.
  1. How do animals gain access to fixed nitrogen if no nitrogen-fixing prokaryotes are known to live inside animals?
  2. They may ingest nitrogen fixers.
  3. They may ingest plants that harbor nitrogen fixers.
  4. They may ingest other animals that ingest nitrogen fixers or plants with nitrogen fixers.
  1. The genomes of archaeans may be unique; nonetheless, they do contain genes that originated within bacteria and have since adapted to unique environments.
  1. Both archaeans and bacteria have plasma membranes and both lack nuclear envelopes. They may or may not have the same cell wall or have identical rRNA sequences.
  1. Extreme halophiles should be expected to be most strongly resistant to plasmolysis in hypertonic environments.
  1. Sulfolobus acidocaldarius is a thermoacidophile that lacks peptidoglycan. What can we concur from this information?
  2. It is an archaean.
  3. The optimal pH of its enzymes will below pH7.
  4. It could inhabit hydrothermal springs.
  1. The primary ecological role of prokaryotes is to break down organic matter.
  1. The recycling of nutrients would be greatly reduced, at least initially, if all prokaryotes on Earth suddeny vanished.
  1. A bacterium lives on a leaf. The bacterium eats the leaf’s waxy coating but inhibits the growth of other microbes on that leaf. The bacterium can cause a fatal disease if it enters the inside of the leaf. When the plant dies, the bacterium and its offspring decompose the plant. What roles do the bacterium play?
  2. The bacterium is a mutualist, a parasite, and a nutrient recycler.
  1. Why can prokaryotes be considered more successful on Earth than humans?
  2. More numerous.
  3. More biomass.
  4. More diverse in metabolism.
  5. Can occupy more diverse habitats.
  1. Closing previously opened containers is not a good way to slow down or prevent bacterial growth in comparison to refrigeration, pickling, irradiation, or using lots of sugar.
  1. Overusing antibiotics can encourage the growth of more antibiotic-resistant strains of bacteria.
  1. Broad-spectrum antibiotics can inhibit the growth of healthy intestinal bacteria and can thus cause a patient to become deficient in certain vitamins.
  1. Genetic variation in bacterial populations can result from transformation, mutations, conjugation, and transduction, but not from meiosis.

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