Study guide 6

What are some basic features of Prokaryotic cells?

They lack a nucleus, are unicellular, have a size of 0.5-5 um, and may have specialized internal membranes.

What are the two types of cell walls in bacteria?

Gram-positive (thick peptidoglycan layer) and Gram-negative (thin peptidoglycan with an outer membrane).

What are plasmids?

Plasmids are small, circular DNA molecules that can contain several genes and can be exchanged with other cells.

What is an endospore?

An endospore is a dormant structure formed under harsh conditions, allowing survival until conditions improve.

How do Prokaryotes replicate their cells?

They replicate through binary fission, a process in which the cell divides into two identical cells.

What is transformation in Prokaryotic genetic diversity?

Transformation is the uptake of free DNA from the environment by a cell.

What is conjugation in Prokaryotic genetic diversity?

Conjugation is the direct transfer of DNA between two cells via a pilus.

What is transduction in Prokaryotic genetic diversity?

Transduction is the transfer of DNA from one bacteria to another via a bacteriophage.

What is the difference between an obligate aerobe and an obligate anaerobe?

Obligate aerobes require oxygen to survive, while obligate anaerobes cannot tolerate oxygen.

What is nitrogen fixation?

Nitrogen fixation is the conversion of inert atmospheric nitrogen into ammonia, which can be used by plants.

What is a photoautotroph?

An organism that obtains energy from light and uses carbon dioxide as its carbon source.

What is a chemoautotroph?

An organism that obtains energy from chemical compounds and uses carbon dioxide as its carbon source.

What is a photoheterotroph?

An organism that obtains energy from light but requires organic compounds as a carbon source.

What is a chemoheterotroph?

An organism that obtains both energy and carbon from organic compounds.

List at least 4 differences between Bacteria and Archaea.

1. Bacteria have peptidoglycan in their cell walls; Archaea do not. 2. Bacteria typically inhibit environments at 100°C or less; Archaea can thrive in extreme environments. 3. Bacteria have different RNA polymerases than Archaea. 4. Bacteria do not have introns in their genes, whereas some Archaea do.

How do Prokaryotes act as decomposers?

Prokaryotes break down dead organic matter, recycling nutrients like carbon and nitrogen back into the ecosystem.

What do Primary Producers do in an ecological system?

Primary producers, such as plants and some prokaryotes, convert sunlight or inorganic substances into organic compounds.

What is symbiosis?

Symbiosis is a close interaction between two different species, where one is referred to as the host and the other as the symbiont.

What is mutualism? Provide an example.

Mutualism is a relationship where both organisms benefit, such as gut bacteria aiding digestion.

What is commensalism? Provide an example.

Commensalism is a relationship where one organism benefits and the other is not significantly harmed, such as skin bacteria.

What is parasitism? Provide an example.

Parasitism is a relationship where one organism benefits at the expense of another, such as tuberculosis bacteria infecting humans.

What is the gut microbiome?

The gut microbiome is the community of microorganisms living in the digestive tracts of humans and other animals.

What is the difference between probiotics and prebiotics?

Probiotics are live beneficial bacteria, while prebiotics are non-digestible fibers that feed these bacteria.

List some examples of Prokaryotes acting as pathogens towards humans.

Examples include Mycobacterium tuberculosis (lung infection), Borrelia burgdorferi (Lyme disease), and Clostridium botulinum (causing paralysis).

What is the difference between an endotoxin and an exotoxin?

Endotoxins are part of the bacterial cell wall and released when the cell is destroyed, while exotoxins are secreted toxins from living bacteria; an example of an exotoxin is the toxin produced by C. botulinum.

What are some beneficial uses of Prokaryotes in human society?

Prokaryotes are used in bioremediation, fermentation, biotechnology, and genetic engineering.